Please ensure Javascript is enabled for purposes of website accessibility.
Search
Search
Search

GIA 4Cs Diamond Blog

GIA 4Cs Diamond Blog

1 carat diamond engagement ring with diamonds set in the prongs and shank.
Diamond Color: Seven Things You Need to Know

If you’re shopping for a diamond engagement ring, you need to know about what diamond color is if you want to understand quality and how diamonds are valued. If you are curious about what colors diamonds come in and how color grade impacts value, check out our seven essential things about diamond color you should know.

In this blog we cover:

  1. Diamond value is based (in part) on the absence of color.
  2. A diamond’s color grade should be determined by a grading laboratory.
  3. Colored diamonds are graded and valued differently from colorless diamonds.
  4. Treatments can improve diamond color.
  5. Diamond fluorescence has little to no impact on diamond color.
  6. Engagement ring settings can influence the perception of diamond color.
  7. To be sure of a diamond’s color, get a GIA grading report.

1. Diamond value is based (in part) on the absence of color

Diamond color is important: Most diamonds used in engagement rings are near-colorless with hints of yellow or brown. All things being equal, the more colorless a diamond is, the rarer it is, and this rarity will be reflected in its price.

GIA D-to-Z diamond color scale.

The GIA D-to-Z Color Scale allows for precise measurement of diamond color. Illustration: GIA

GIA’s D-to-Z Color Scale is used to measure the degree of colorlessness of a diamond. The letter “D” represents a colorless diamond, with each following letter representing a diamond that has slightly more yellow or brown.

GIA organizes diamond color into five groups:

  • Colorless (D-F): The most rare, and therefore the most valuable
  • Near-colorless (G-J): Color is often unnoticeable except by trained graders
  • Faint (K-M): Color is still difficult to see by the untrained eye
  • Very Light (N-R): Subtle color can be seen in larger stones by an untrained eye
  • Light (S-Z): Color can be seen in stones of different sizes. The diamonds appear slightly yellow or brown but do not have sufficient color to be considered a “fancy” colored diamond
GIA D-to-Z diamond color scale showing diamonds at either end of the grading spectrum.

When diamonds at either end of the grading spectrum are placed side by side, it is easy to see the differences in diamond color. Photo: GIA

2. A diamond’s color grade should be determined by a grading laboratory

The distinctions between diamond color grades can be so subtle that they are undetectable to the untrained eye. But they do make a very big difference in diamond price. That’s why determining a diamond’s color grade is best left to a gemological laboratory, like GIA, that has the expertise and processes to ensure objective, unbiased color grading.

In working to evaluate what color a diamond is, GIA graders follow a strict protocol that dictates the type of lighting and neutral background used, as well as precisely how the diamond should be held and viewed during the assessment. A color grade is determined by comparing the diamond to masterstones – a set of color-comparison diamonds of known position on the GIA D-to-Z color grading scale – when all are placed table down in a grading tray. This viewing position reduces the complex appearance of a faceted colorless to near-colorless diamond when viewed face up.

A 6.75 carat round brilliant cut diamond engagement ring featuring a diamond melee halo and band.

One look at this 6.75 carat (ct), F-color, SI-clarity round brilliant and you’ll know why diamonds are the universal symbol of love. Courtesy: 1stdibs.com

3. Colored diamonds are graded and valued differently from colorless diamonds

Diamond color is arguably the most important factor in colored diamonds. Some common colors that diamonds come in are yellow, brown, pink, red, blue, orange, purple, green, gray or black. This does not include diamonds in the normal color range that are slightly yellowish, slightly brownish or slightly grayish. When the color is natural, the diamonds are called fancy-color diamonds, fancy diamonds or fancies.

Colored diamonds come in a rainbow of hues.

Colored diamonds come in a rainbow of hues. Photo: Robert and Orasa Weldon/GIA

GIA grades colored diamonds differently from colorless diamonds. Unlike GIA’s D-to-Z grading system for colorless to light yellow diamonds, which is based on the absence of color when the diamond is viewed table down, the grading system for colored diamonds is based on the presence of color when the diamond is viewed face up. Terms used by GIA to describe colored diamonds include: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Dark, Fancy Intense, Fancy Deep and Fancy Vivid.

What to look for in colored diamonds? In general, the more color a colored diamond has, the better. Fancy Deep and Fancy Vivid diamonds, for example, have more color than Fancy Light diamonds—and are usually more valuable. However, tone is also important: For example, a diamond that is extremely dark (Fancy Dark) may be less desirable than a lighter stone graded Fancy Intense.

A 3.66 ct Fancy Yellow diamond engagement ring with two halos containing 0.37 carats of yellow diamonds and 1.50 carats of colorless diamonds.

Colored diamonds can be far more expensive than colorless diamonds. Here a 3.66 ct Fancy Yellow glows like a ray of sunshine. Two halos encircle it: the inner containing 0.37 carats of yellow diamonds; the outer, 1.50 carats of colorless diamonds. Courtesy: 1stdibs.com

Fancy-color diamonds are, for the most part, far rarer than diamonds in the D-to-Z color range. Some experts estimate that only two percent of total rough diamond production is fancy colored. Since rarity influences price, it’s not surprising that spectacular blue, pink, green, orange and other colored diamonds can sell for millions of dollars at auction.

The Pink Star ring, which sold at a Sotheby’s auction for $71 million, contains a 59.60 ct Fancy Vivid pink diamond graded by GIA.

The GIA-graded Fancy Vivid pink 59.60 ct Pink Star diamond sold for $71 million at the April 4, 2017 Sotheby’s auction in Hong Kong. Courtesy: Sotheby’s

4. Treatments can improve diamond color

Diamond color can be altered by treatments. All else being equal, diamonds that have not been treated are more expensive than diamonds that have been treated. Legally, the seller must disclose any treatments. If you are aware what diamond color is, it’s easier to understand how they have been treated. 

High pressure, high temperature (HPHT) processing is perhaps the most common technique used to alter, enhance or remove color. HPHT treatment can change some brown diamonds into colorless ones or into other colors like yellow, greenish yellow or green. This process is also associated with treated pink, blue and orange-yellow diamonds. The resulting color is considered permanent, but HPHT treatment should always be disclosed.

Annealing is another process that uses controlled heating and cooling to change the color of a gem material, especially after irradiation. Irradiating a diamond or coating it are other methods used to enhance a diamond’s color.

.

A 6.61 ct Fancy yellow brown diamond (left) before annealing and the same diamond (right), graded L (faint yellow) after annealing.

Before HPHT annealing to remove color, this 6.61 ct diamond was a Fancy yellow brown (left). After annealing (right), GIA graded the diamond an L (faint yellow). Photo: Robert Weldon/GIA

5. Diamond fluorescence has little to no impact on diamond color

Diamond fluorescence is visible light temporarily emitted by some diamonds when they are exposed to ultraviolet (UV) rays from the sun, fluorescent lamps or other sources. This emitted light can display various colors (often blue in diamonds), intensities (faint to very strong) and distribution patterns. When the light source is removed, the fluorescence is no longer visible.

Many in the diamond trade believe that strong blue fluorescence can make a light yellow diamond look closer to colorless when exposed to a UV source such as sunlight. Blue and yellow are color opposites and tend to cancel each other out, so blue fluorescence masks the yellow color. In rare cases, some diamonds with extremely strong fluorescence may appear slightly hazy or oily. Fewer than 0.2% of the fluorescent diamonds submitted to GIA exhibit this effect.

.

A group of seven diamonds shown under daylight-equivalent illumination (left) and exposed to long-wave UV irradiation (right).

The same group of seven diamonds is shown here under daylight-equivalent illumination (left) and when exposed to long-wave UV irradiation (right). Photos: Kevin Schumacher/GIA

To answer questions from consumers and the trade about the impact of fluorescence on diamond color in the D-to-Z range, GIA conducted extensive observer testing. Here’s what its researchers found: “For the average observer, meant to represent the jewelry buying public, no systematic effects of fluorescence were detected [on the face-up appearance of the groups of diamonds]. Even the experienced observers did not consistently agree on the effects of fluorescence from one stone to the next.” As a result, GIA considers diamond fluorescence to be an identifying characteristic, not a grading factor – meaning, it has little to no impact on what color the diamond is.

6. Engagement ring settings can influence the perception of diamond color

Diamonds are highly reflective – their facets are essentially an arrangement of tiny mirrors reflecting light and the surroundings. So it should come as no surprise that the color of a ring’s prongs and shank can influence the color you see in the diamond. A white metal like platinum or white gold can emphasize the absence of color in a diamond that is colorless or near-colorless, while a gold band might make a diamond lower on the D-to-Z scale appear more yellow.

Learn more about how metal affects a diamond’s color appearance.

A 8.03 carat D color marquise cut diamond engagement ring set in platinum, flanked by two tapered baguettes weighing 0.72 carats.

The 8.03 ct marquise cut diamond in this engagement ring is D color. It is flanked by two tapered baguettes weighing a total of 0.72 carats. The platinum band and prongs highlight the beauty of the diamond. Courtesy: 1stdibs.com

7. To be sure of a diamond’s color, get a GIA grading report

A GIA Diamond Grading Report and GIA Diamond Origin Report provides an in-depth assessment of a diamond’s quality based on the 4Cs: diamond color, clarity, cut and carat weight. A report not only contains an objective color grade, but it also discloses other identifying characteristics like fluorescence, as well as any treatments detected. Learn what diamond color information is included in a GIA report.

An engagement ring is profoundly intimate and symbolic – it represents your love and commitment. A GIA Diamond Grading Report lets you make this most important purchase with peace of mind.

Now that you understand  what diamond color is and  its importance, here are 12 tips for buying an engagement ring.

Lead image courtesy of 1stdibs.com

Read More
Read More
A 2.78 carat Internally Flawless round brilliant cut diamond
What Is a GIA Diamond ?

GIA diamond is a term you’ll find when engagement ring shopping – short for a diamond graded by GIA, the creator of the 4Cs and the independent, diamond authority. Learn more about GIA diamonds and why savvy shoppers rely on GIA.

In this blog, we answer the following questions:

What is a GIA diamond ?
Is every diamond a GIA diamond ?
What does it mean for a diamond to be a “GIA certified diamond”?
How does GIA ensure objectivity when grading diamonds?
Do I really need to get a diamond graded?
How do you get a diamond “GIA certified”?
Do “GIA certified” diamonds cost more?
Where can I find a GIA diamond ?

What is a GIA diamond ?

As mentioned above, a GIA diamond is really shorthand diamond sellers use to describe diamonds that have been graded by GIA. GIA is an independent, nonprofit organization that conducts gem research, educates gem professionals and sets the standards for determining diamond quality. One of GIA’s main functions is the grading of diamonds. You may have already heard or learned about the 4Cs of diamond quality: color, clarity, cut and carat weight. GIA created this standard, along with the scientific procedures for evaluating each “C” and the grading terminology used to describe them.

GIA does not mine diamonds, nor does it buy, sell or trade them commercially. It doesn’t appraise diamonds and is not otherwise involved in diamond pricing or valuation. GIA operates independently of these commercial interests, ensuring that its diamond quality assessments are completely objective and unbiased.

If you want to know the quality of the diamond you’re considering – and you should, because quality and price go hand in hand – then you should look for GIA-graded diamonds and the GIA diamond grading reports that will accompany them.

Is every diamond a GIA diamond ?

No, not all diamonds have been graded by GIA. Although it may seem that way given the sheer quantity of GIA-graded diamonds in the marketplace. This volume is a testament to the trust jewelers and their customers place in GIA’s accurate and independent grading services.

To be sure your diamond was graded by GIA, ask to see its GIA grading report. In addition to a full assessment of the diamond’s 4Cs, the GIA report contains a unique number, which is also sometimes inscribed on the diamond’s girdle. You can use the report number to access GIA’s online global report database, GIA Report Check, to verify that the diamond is GIA graded and view all its grading details.

A 1 carat (ct) diamond engagement ring set with 0.50 carats of diamond melee.

Round is the most popular diamond shape for engagement rings and a GIA report will contain a cut grade for round brilliant cut diamonds. This 1 carat (ct) diamond center stone is cradled by another 0.50 carats of diamond melee. Courtesy: BlueNile

What does it mean for a diamond to be a “GIA certified diamond”?

“GIA certified diamond” is a misnomer. GIA doesn’t certify diamonds – it grades them. The terms “GIA certified” and “GIA cert” are commonly used in the jewelry industry to refer to diamonds that have undergone GIA’s rigorous grading process and to the reports that accompany them.

GIA itself does not use the word “certificate” to describe the document it issues. GIA examines the diamond, assesses its qualities based on the 4Cs, and describes it. It does not certify the diamond or its value. Rather, like other scientific laboratories, GIA issues a report on the results of its evaluation of a particular diamond and believes “report” is the appropriate term to describe its grading results.

An Internally Flawless, D color 2.78 ct round brilliant cut diamond.

This GIA-graded, Internally Flawless 2.78 ct round brilliant cut diamond received GIA’s highest grade for color: D. Photo: Robert Weldon/GIA. Courtesy: Rogel & Co. Inc.

GIA Diamond Reports

How does GIA ensure objectivity when grading diamonds?

GIA has robust procedures in place to ensure a diamond’s anonymity and the objectivity of the grading process. Upon arrival to the laboratory, the diamond is placed in a transparent storage case and all references to its owner are removed or concealed. It is assigned a bar-coded label that is used to track it throughout the process. All these precautions ensure that a GIA grading report objectively represents a diamond’s characteristics.

A 7.82 ct cushion cut diamond engagement ring.

The cushion cut diamond – a historical favorite – is trending again, and it’s easy to see why when you look at this 7.82 ct stunner, which GIA graded J color, VS2 clarity. Courtesy: 1stdibs.com

GIA diamond graders meticulously assess the color, clarity, cut, and carat weight of the diamond. More-experienced staff gemologists may review any or all of the grading information and render independent opinions. A grade is not issued until sufficient consensus is reached.

Watch a diamond go through GIA’s grading processes.

Do I really need to get a diamond graded?

A diamond engagement ring is one of the most important purchases you’ll make. It may also be one of the most expensive. Because of this, you’ll want to be sure that you’re getting a good value for the diamond you’re considering.

A GIA diamond grading report gives you all the important information you need to know about a diamond’s 4Cs, as well as its fluorescence, any treatments and more. With a GIA diamond grading report you can be sure that your diamond is a natural diamond. That’s because GIA has examined and tested the diamond using the most sophisticated instruments and procedures available, informed by the Institute’s ongoing scientific research.

Since a GIA diamond grading report is an unbiased assessment of a stone’s quality characteristics, it lets you compare one GIA-graded diamond to another. This empowers you to compare the quality of loose diamonds, and decide which one is the best value and right for you.

Making sure the diamond you’re eyeing comes with a GIA diamond grading report is like getting an independent inspection before you buy a car or house. It’s a smart step in your purchase process – and many insurance companies will require a GIA grading report as a basis for insuring your diamond.

An H-color, VS2 clarity, 1.10 ct princess cut diamond engagement ring surrounded by 0.96 carats of diamond melee.

GIA grades diamonds of all shapes, and the square-shaped princess cut is one of the more popular for engagement rings. This H-color, VS2 clarity, 1.10 ct princess cut diamond is surrounded by another 0.96 carats of diamond melee. Courtesy: TrueFacet.com

How do you get a diamond “GIA certified”?

GIA doesn’t certify diamonds, it grades them and anyone can submit a diamond to GIA for grading. You can drop off a stone at any of GIA’s nine laboratories, located in gem and jewelry capitals around the world, or you can ship it to GIA. However, given the complexities of packaging, shipping and insuring diamonds, and because GIA only grades unmounted gems, your best option is to work with your local jeweler to submit the stone on your behalf.

Many diamonds in stores and online will already have a GIA grading report, which you can ask to see prior to purchasing. Your diamond’s report should also be given to you once you complete your purchase.

Do “GIA certified” diamonds cost more?

Again, “GIA certified” is really a misnomer for GIA graded diamonds. There’s a false notion that GIA diamonds cost more, often based on comparing diamonds by price tag alone. The price of a diamond, a car or any other item of value is tied to quality. If you can’t be sure of the quality you’re getting, how do you know if you’re paying too much or getting a good deal? That’s why it’s important to compare prices for diamonds that have the same 4Cs quality characteristics and whose qualities have been accurately and objectively graded by the same independent laboratory like GIA.

Having a diamond graded by GIA is not expensive. GIA charges as little as $48 for a grading report for a diamond weighing 0.70 ct to 0.99 ct, and as little as $80 for a diamond weighing 1.00 ct to 1.49 ct. (Most jewelers factor grading fees into the price of the diamond.) Considering that couples spent an average of $6,351 on an engagement ring in 2017, the cost of a GIA diamond grading report is a small price to pay for peace of mind.

A 3.55 ct emerald cut diamond engagement featuring 24 baguettes and 136 round diamonds on the shank.

This 3.55 ct emerald cut diamond received high grades on its GIA report: F color and VS2 clarity. Another 24 baguettes and 136 round diamonds totaling 1.62 carats decorate the band. Courtesy: 1stdibs.com

Where can I find a GIA diamond ?

Most quality jewelers offer diamonds with GIA grading reports. The GIA Retailer Lookup can help you find retailers in your area who carry GIA-graded diamonds or have GIA-trained staff. Popular e-commerce websites also sell GIA diamonds.

Ready to shop for an engagement ring? Make a smart and beautiful purchase by reading our 12 tips for buying an engagement ring.

Read More
Read More
A 2.00 carat emerald cut diamond engagement ring framed by milgrain and another 0.75 carats of diamonds in the shank.
How to Determine Ring Size: Tips and Ring Size Chart

Getting the ring size right is a must for any engagement ring. After all, you’ve invested a lot in selecting the perfect ring and planning the proposal, so naturally you’ll want the ring to fit right out of the box.

In this blog, we’ll dispel some common myths floating around on the Internet and provide some reliable tips on how to determine her ring size, including an international ring size chart, so you can get it right. (more…)

Read More
Read More
A rose gold band adds a dramatic splash of color when bracketed between two bands in white gold. A subtle touch: The pattern in the rose gold ring is echoed in the diamond wedding bands.
Five Ways to Pair Wedding Bands and Engagement Rings

A lot of love and care went into choosing and giving your engagement ring, so now it’s time to give wedding bands your undivided attention. The choices seem endless, but we’ve gathered some popular looks to help narrow things down for you. (more…)

Read More
Read More
2.32 ct oval pink diamond
Engagement Ring Styles: Seven Irresistible Trends

Love may be eternal, but trendy engagement ring styles are meant to capture the moment you fell in love. Trending diamond shapes include marquise, cushion cut and oval. Pink is in, as are two-tone halo settings. (more…)

Read More
Read More
December birthstones: Turquoise cabochon treated by the Eljen process, 8.08 ct., tanzanite, and zircon.
December Birthstone: What You Need to Know About Tanzanite, Turquoise and Zircon

If you had to pick one December birthstone, which would it be: tanzanite, turquoise or zircon? From the blue to bluish purple of tanzanite, to the intense blue and green of turquoise, to the rainbow varieties of zircon, there’s a color for you. We help you pick one.

In this blog, we cover:

Tanzanite: The Newest December Birthstone
Gemological properties of tanzanite
Tanzanite history & lore
Where tanzanite comes from
Qualities to look for in tanzanite
Tanzanite treatments, care & cleaning

Turquoise: The Historic December Birthstone
Gemological properties of turquoise
Turquoise history and lore
Where turquoise comes from
Qualities to look for in turquoise
Turquoise treatments, care & cleaning

Zircon: The Colorful December Birthstone
Gemological properties of zircon
Zircon history & lore
Where zircon comes from
Qualities to look for in zircon
Zircon treatments, care & cleaning

TANZANITE: THE NEWEST DECEMBER BIRTHSTONE

A trilliant cut tanzanite with an exceptional violetish blue color captivates as the December birthstone. Photo: Robert Weldon/GIA

A trilliant cut tanzanite with an exceptional violetish blue color captivates as the December birthstone. Photo: Robert Weldon/GIA

Gemological properties of tanzanite

Tanzanite is the blue to violet to bluish purple variety of the mineral zoisite. This December birthstone is mined commercially in only one area of the world — the Merelani Hills of Tanzania — from where it gets its name.

Tanzanite’s appearance is influenced greatly by its pleochroism – the different colors some gemstones show when viewed from different directions. Tanzanite can be violetish blue or deep blue – similar to a sapphire color – or much more purplish. Often, both the violetish blue and purple are readily visible in a fashioned stone when it is gently rocked and tilted. This December birthstone is rather fragile, ranking 6 to 7 on the Mohs scale of hardness; a diamond is a 10. The scale is exponential, meaning that a diamond is many times harder than tanzanite. Tanzanite’s toughness (the ability of a gem material to resist breaking, chipping or cracking) is fair to poor because it has one direction of cleavage (the tendency of a crystalline mineral to break along atomic planes) and is sensitive to sudden temperature changes.

Gemologists love tanzanite because it shows different colors when viewed from different directions.

5.59 carat (ct) oval tanzanite contrasted with 28 channel set tapered baguettes and 12 round brilliant cut diamonds.

The vault of the evening sky and a field of stars is conjured by this 5.59 carat (ct) oval tanzanite contrasted with 28 channel set tapered baguettes and 12 round brilliant cut diamonds. Courtesy: EraGem.com

Tanzanite history & lore

Tanzanite may be a relative newcomer to the world of colored stones, but it was one of the most exciting gem discoveries of the 20th century. Blue stones emerging from Tanzania were identified as the mineral zoisite in 1962 by Polish expatriate George Kruchluk. Not until 1967, though, did prospector Manuel D’Souza — with the help of a Masai tribesman — locate the primary source: the Merelani Hills. D’Souza filed four mining claims. Word spread and 90 more claims were quickly registered – even though at the time there was some confusion as to the identity of the gem material.

Tiffany & Co. believed that tanzanite had international appeal and became its main distributor. In 1968, Tiffany launched a major advertising campaign to promote it. With its vivid colors, high clarity and potential for large cut stones, tanzanite quickly became a sensation. Today, it is not only a December birthstone, but it is also the gem for the 24th wedding anniversary.

Where tanzanite comes from

Grass-covered hillsides, scrub brush, rocky soil and an occasional tree form the landscape of the Merelani Hills. In the major mechanized operations there, thousands of workers recover tanzanite from mines dug over a hundred meters deep into the earth. North of the mines tower the snow-covered slopes of Mount Kilimanjaro.

Peeking out from the clouds is the domed summit of Mount Kilimanjaro. Tanzanite is mined in its shadow.

Peeking out from the clouds is the domed summit of Mount Kilimanjaro. Tanzanite is mined in its shadow. Photo: Eric Welch/GIA

Qualities to look for in tanzanite

Color: The most prized color in tanzanite is a pure blue similar to fine sapphire or an intense violet-blue. Tanzanite with a bluish purple body color is also popular, but less valuable. In any hue, pale colors are less prized than saturated ones.

4.91 ct tanzanite, which mimics the deep blue of fine sapphire, and its regal frame of diamonds.

Be mesmerized by the rich color of this 4.91 ct tanzanite, which mimics the deep blue of fine sapphire, and its regal frame of diamonds. Courtesy: 1stdibs.com

Clarity: Tanzanite is usually free of eye-visible inclusions. If any inclusions are present – especially those that pose a durability problem, such as fractures – they typically lower the value.

Cut: Tanzanite is available in a wide range of shapes, but cushion and oval cuts are more common. Because of its pleochroism, cutting direction determines the gem’s overall face-up color. Cutting a tanzanite to emphasize the bluish purple color usually wastes less rough than cutting it to get a pure blue or violetish blue color. The cutter has to make a choice between a smaller top-color gem and a larger bluish purple one.

Carat Weight: Fine tanzanite with a strong, deep color can be found in pieces weighing 5.00 carats or more. Smaller sizes in less saturated colors are commonly seen in mass market jewelry.

Some 17.67 carats of tanzanite blossom in Sir Zoltan David’s magical "Flowerfly" necklace.

Some 17.67 carats of tanzanite blossom in Sir Zoltan David’s magical “Flowerfly” necklace. The piece won the Tanzanite Foundation’s “Be Born to Tanzanite” Competition in 2007. Photo: Robert Weldon/GIA. Courtesy: Zoltan David

Tanzanite treatments, care & cleaning

Tanzanite is stable under normal wearing conditions, which means it’s resistant to the effects of normal heat, light and common chemicals. Still, the December birthstone may crack if exposed to very high temperatures or sudden temperature changes. It can be attacked by hydrochloric and hydrofluoric acids.

Warm, soapy water is always the best way to clean this December birthstone. Ultrasonic and steam cleaners are never recommended for tanzanite.

Untreated, tanzanite is typically brown. Tanzanite is routinely heat treated to modify its color to a predominantly blue to bluish purple. The treatment is stable with no additional durability concerns.

TURQUOISE: THE HISTORIC DECEMBER BIRTHSTONE

A shoreline of diamonds surround an ocean of turquoise in this captivating ring.

A shoreline of diamonds surround an ocean of turquoise in this captivating ring. Courtesy: Arya Esha

Gemological properties of turquoise

Turquoise is found in only a few places on Earth: dry and barren regions where acidic, copper-rich groundwater seeps downward through deeply altered or broken rocks where it reacts with minerals that contain phosphorus and aluminum. The result of this process is a porous, semitranslucent-to-opaque hydrous phosphate of copper and aluminum.

This December birthstone owes its texture to its structure and composition. Turquoise is an aggregate of microscopic crystals that form a solid mass. If the crystals are packed closely together, the material is less porous, so it has a finer texture. Fine-textured turquoise has an attractive, waxy luster when it’s polished. Turquoise with a less-dense crystal structure has higher porosity and a coarser texture, resulting in a duller luster when it’s polished.

Porosity and texture don’t just affect appearance: They also affect the durability of turquoise. This December birthstone is fairly soft—it ranks 5 to 6 on the Mohs scale of hardness. Turquoise with a coarse texture might have poor toughness, too, so it fractures easily. Samples with finer texture have fair to good toughness.

Gemologists love this December birthstone because turquoise often contains matrix: spiderweb-like veins that provide evidence of the rock in which it formed. They also like how turquoise is colored by copper, which creates some of the most vivid blues and greens in the gem kingdom.

Whether opaque, semitranslucent or checkered with spiderwebs, turquoise enchants

Whether opaque, semitranslucent or checkered with spiderweb-like veins, turquoise enchants. Composite photo: Eric Welch, Robert Weldon, Terri Weimer/GIA, Dr. Edward J. Gübelin collection. Courtesy (far right): Barlow’s

Turquoise history & lore

Turquoise has been cherished for millennia. The pharaohs and other rulers of ancient Egypt adorned themselves with it. Chinese artisans carved it more than 3,000 years ago.

This December birthstone was thought to possess many beneficial powers, like guaranteeing health and good fortune. From the 13th century on, it was believed to protect the wearer from falling (especially off horses), and would break into several pieces at the approach of disaster. Hindu mystics maintained that seeing a turquoise after beholding the new moon ensured fantastic wealth.

Turquoise played an important role in the lives of Native Americans. The Apache thought turquoise could be found by following a rainbow to its end. They also believed that attaching the December birthstone to a bow or firearm made one’s aim more accurate. The Pueblo maintained that turquoise got its color from the sky, while the Hopi thought the gem was produced by lizards scurrying over the earth.

An artisan from the Zuni tribe made this turquoise brooch.

An artisan from the Zuni tribe made this turquoise brooch. Courtesy: 1stdibs.com

Turquoise adorns the funerary mask of King Tut, who ruled Egypt more than 3,000 years ago. It also appears in jewelry belonging to more modern royalty, such as the Jordan turquoise demi-parure (turquoise, diamond and sapphire necklace and earrings) in the collection of Britain’s Queen Elizabeth II. Wallace Simpson (1896-1986), Duchess of Windsor, wore a famous amethyst and turquoise necklace made by Cartier. Turquoise is also the gem of the 11th wedding anniversary.

A dazzling display of color, Cartier’s bib necklace for the Duchess of Windsor features a sea of turquoise cabochons and faceted amethyst.

A dazzling display of color, Cartier’s bib necklace for the Duchess of Windsor features a sea of turquoise cabochons and faceted amethyst. Courtesy: N. Welsh, Cartier Collection © Cartier

Where turquoise comes from

Turquoise has been mined in the Nishapur district of Iran for more than 1,000 years. The even-colored, intense blue turquoise from this region is dubbed “robin’s egg blue,” “sky blue” and “Persian blue.” Trade professionals now use these terms to describe turquoise of this color – regardless of the source.

This is the view on the way to Nishapur.

This is the view on the way to Nishapur. Courtesy: Dr. Edward J. Gübelin Collection

Although New Mexico was the largest producer of turquoise in the U.S. until the 1920s, today most of the U.S. production of this December birthstone comes from Arizona and Nevada. Mines have evocative names like Dry Creek, Easter Blue, Emerald Valley and Fox. The Kingman mine in Arizona is a historically important source that is known for producing intense blue turquoise. Now closed to turquoise mining, the Sleeping Beauty mine was a prolific producer for more than four decades.

The intense blue turquoise beads in this necklace came from Arizona’s Sleeping Beauty mine.

The intense blue turquoise beads in this necklace came from Arizona’s Sleeping Beauty mine. Photo: Robert Weldon/GIA. Courtesy: Somewhere In The Rainbow

China is now the world’s largest producer of fine turquoise. Hubei Province, in central China, is the source of most of the gem-quality turquoise currently being mined there.

Qualities to look for in turquoise

Color: The color of turquoise usually ranges from light to medium blue or greenish blue. It’s often mottled, and sometimes it has dark splotches. It might also have veins of matrix running through it.

The most-prized turquoise color is an even, intense, medium blue, with no matrix and the ability to take a good polish. But some consumers prefer a greenish blue, and some contemporary designers seek turquoise referred to as “avocado” and “lime green.”

Clarity: Turquoise can be semitranslucent to opaque. Semitranslucent stones are preferred.

Note the even color in the clusters of turquoise dangling from gold chains in this one-of-a-kind piece.

Note the even color in the clusters of turquoise dangling from gold chains in this one-of-a-kind piece. Courtesy: Denise James

Cut: Turquoise is most often fashioned as cabochons. The smoothly rounded dome shape sets off turquoise’s color, texture and any matrix beautifully. In addition, manufacturers and artisans fashion turquoise rough into round or oblong beads for necklaces, and into small, flat pieces that are popular as jewelry inlays. Other rough material might be tumbled into “nuggets” or polished as free-form shapes that reflect the shape of the original rough. There are also examples of top-color blue turquoise engraved with Persian or Arabic inscriptions that are then inlaid with gold.

Carat Weight: Turquoise is available in a wide range of sizes. All sizes, even very small ones, are used in Native American jewelry, and large pieces have been popular for carvings. For any size, the quality and evenness of the color is the overriding value factor.

Rich blue turquoise surrounded by 24K gold makes these earrings a mesmerizing sight.

Rich blue turquoise surrounded by 24K gold makes these earrings a mesmerizing sight. Courtesy: Lika Behar

Turquoise treatments, care & cleaning

A colorless wax or polymer is often used to improve the color and luster of turquoise. Other treatments include applying epoxy to thin turquoise slices to strengthen them, applying coatings of lacquer or epoxy, and filling cavities with imitation pyrite inclusions made of metal-filled epoxy.

It’s safe to clean turquoise jewelry with warm, soapy water, but this December birthstone should never be cleaned with steam or ultrasonic cleaners. Heat or solvents can damage the treated surfaces on some turquoise.

Turquoise is generally stable to light, but high heat can cause discoloration and breakage. Turquoise can be damaged by acids, and it can be discolored by certain chemicals, cosmetics and even skin oils or perspiration.

ZIRCON: THE COLORFUL DECEMBER BIRTHSTONE

A 19.76 ct orangy brown zircon is ringed by 0.51 carats of diamonds.

A 19.76 ct orangy brown zircon is ringed by 0.51 carats of diamonds. Courtesy: 1stdibs.com

Gemological properties of zircon

Zircon comes in a wide and varied palette of yellow, green, red, orange, brown and blue hues, making it a favorite among collectors and knowledgeable consumers. This December birthstone is 6 to 7.5 on the Mohs scale of hardness.

The zircons in this colorful array originate from Sri Lanka, Cambodia, Thailand, Tanzania and other locations.

Zircon comes in a wide array of attractive colors. Photo: Robert Weldon/GIA, Dr. Edward J. Gübelin Collection.

Colorless zircon is known for its brilliance and flashes of multicolored light, called fire. These two zircon properties are close enough to the properties of diamond to account for centuries of confusion between the two gems.

This 11.41 ct oval blue zircon with its diamond halo is like a lake that invites the viewer to peer into infinity. The tsavorite garnet side stones are leafy touches to the icy scene.

This 11.41 ct oval blue zircon with its diamond halo is like a lake that invites the viewer to peer into infinity. The tsavorite garnet side stones are leafy touches to the icy scene. Courtesy: Omi Privé

Gemologists love zircon because its radioactive trace elements are a geologic clock that tells us about the early Earth. This December birthstone also has very high luster, high refractive indices (the measure of the extent to which light is bent as it leaves a gemstone at an angle other than perpendicular to the surface) and strong dispersion, which is responsible for the brilliance and rainbow flashes of fire.

Zircon history & lore

The origins of the word zircon have elicited colorful debate. Some scholars believe it comes from the Arabic word zarkun, meaning “cinnabar” or “vermilion.” Others think the source is the Persian word zargun, or “gold colored.” Considering the color range for this December Birthstone, either derivation seems possible.

Zircon comes with pleasing lore. In the Middle Ages, it was thought to lull one into a deep sleep and scare off evil spirits. In the Hindu religion, zircon alternates with hessonite garnet as one of the nine gems of the navaratna. When worn together, the nine gems protect the wearer and bring good health, wealth and wisdom.

Victorians had a fondness for blue zircon. Fine specimens can be found in English estate jewelry from the 1880s.

Regal rings like this show why blue zircon is a popular gem

Regal rings like this show why blue zircon is a popular gem. Courtesy: LeVian

Where zircon comes from

Sri Lanka’s wealth of gems is legendary: Sapphire in various colors, ruby, alexandrite, spinel, tourmaline, moonstone and quartz are some of the gem minerals unearthed there. So is zircon. Elahera, a region in central Sri Lanka, is one of the country’s most productive areas. Mountains, jungles and restless streams make for a dramatic landscape.

An artisanal miner searches for gems in the Elahera region of Sri Lanka.

An artisanal miner searches for gems in the Elahera region of Sri Lanka. Photo: Vincent Pardieu/GIA

Australia’s Harts Range is known for producing zircons in yellow-brown, orangy brown, pink and purple. Go there and you’ll see open savannahs, dry stream beds and low-lying hills that meet the horizon. Zircon Hill is where the gem is mined. The nearby city of Alice Springs is known for its outback culture, aboriginal art and quirky sporting events like a regatta race held in a dry river bed.

Zircon is often located near sapphire sources. Countries where the two overlap include Sri Lanka, Myanmar, Vietnam, Cambodia and Australia.

Qualities to look for in zircon

Color: Some zircons display warm autumnal earth tones such as yellowish and reddish brown. Red and green zircons have market value as collectors’ stones, and cat’s-eye zircons occasionally appear on the market. There are also colorless zircons.

A brisk autumn day, a fireplace and apple cider would be the perfect backdrop for this ring, which features a 7.96 ct zircon.

A brisk autumn day, a fireplace and apple cider would be the perfect backdrop for this ring, which features a 7.96 ct zircon. Photo: Robert Weldon/GIA. Courtesy: Richard Krementz Gemstones

Although collectors clearly love zircon’s variety of colors, consumers seem most enamored of just one hue: blue. Gem dealers report that at least 80 percent of the zircons they sell are blue. Because they’re in greater demand, blue zircons usually command higher prices than any of the other varieties.

A blue zircon takes center stage in the “Reine de Glace” pendant designed by Lisa Krikawa.

A blue zircon takes center stage in the “Reine de Glace” pendant designed by Lisa Krikawa. Courtesy: Krikawa Jewelry Designs. Blue zircon by John Dyer & Co.

Clarity: Zircons are relatively free of inclusions. But many untreated zircons have a cloudy or smoky appearance that, if extreme, can be a negative factor with buyers. In Victorian times, this smokiness made zircon a popular gem for mourning jewelry. Today, most faceted zircon is free of inclusions that are visible to the unaided eye. Eye-visible inclusions cause a drop in zircon value. Rarely, zircon might contain long, parallel inclusions that create a cat’s-eye effect when the stone is cut as a cabochon.

Cut: It’s a challenge to cut zircon because the gem is brittle. Cutters usually fashion zircon in the brilliant style to take advantage of its brilliance and fire. Zircon can also be found in step cuts, which have rows of parallel facets, and mixed cuts, which are a combination of brilliant and step-cut facets.

A richly colored 7.23 ct zircon set in an ornate 18K gold ring looks like it belongs on the finger of European royalty.

A richly colored 7.23 ct zircon set in an ornate 18K gold ring looks like it belongs on the finger of European royalty. Courtesy: 1stdibs.com

Carat Weight: The supply of this December birthstone is generally limited, and typical zircon sizes depend on color. Blue or green stones normally range from one carat to 10 carats, with yellows and oranges up to around five carats. Reds and purples are usually smaller.

Zircon treatments, care & cleaning

Warm, soapy water is recommended for cleaning zircon. Ultrasonic and steam cleaners are not recommended for this December birthstone.

Zircon is commonly heat treated to produce blue and colorless varieties, as well as orange, yellow and red. The gem is generally stable when exposed to light, but some heat-treated stones might revert to their original colors (usually light brown) after prolonged exposure to bright light. Exposure to heat can alter the color of some zircon. Zircon is stable when exposed to chemicals.

Because zircon tends to abrade, it is best to avoid wearing it in rough conditions, such as while gardening, playing sports or doing dishes.

The color of the 14.48 ct zircon in this ring evokes a forest … fields … grassy expanses.

The color of the 14.48 ct zircon in this ring evokes a forest … fields … grassy expanses. Courtesy: 1stdibs.com

Ready to go shopping for the December birthstone?  Be sure to take our Tanzanite Buying Guide and Turquoise Buying Guide with you when you go!

Read More
Read More
18K White Gold 10.09ct Cushion Diamond Halo Engagement Ring
Engagement Ring Buying: How to Compare Loose Diamonds

Comparing loose diamonds for an engagement ring? Don’t be dismayed by the dizzying array of choices. The important thing is understanding how to compare loose diamonds. Here are six easy steps to help you pick a diamond that’s beautiful and a smart purchase.

(more…)

Read More
Read More
November birthstones: pink topaz, Imperial topaz and citrine.
November Birthstone: What You Need to Know About Topaz and Citrine

Those with a November birthstone have two beautiful options to choose from: topaz and citrine. Topaz comes in a rainbow of colors; citrine is known for its charming yellow and orange hues. The two gems give you countless options. Your challenge will be deciding which one to pick. We offer help.

In this post, we cover

Gemological properties of topaz
Topaz history & lore
Where topaz comes from
Qualities to look for in topaz
Topaz treatments, care & cleaning
Gemological properties of citrine
Citrine history & lore
Where citrine comes from
Qualities to look for in citrine
Citrine treatments, care & cleaning

November birthstone: Gemological properties of topaz

The November birthstone topaz has an exceptionally wide color range that, in addition to brown, includes various tones and saturations of blue, green, yellow, orange, red, pink and purple. Colorless topaz is plentiful, and is often treated to give it a blue color.

Pictured here are some of the many colors of topaz, the November Birthstone. From left to right: a 9.21 ct colorless emerald cut, a 15.01 ct light blue emerald cut, a 18.41 ct purplish pink emerald cut and a 12.54 ct orange-red emerald cut.

Pictured here are some of the many colors of topaz. From left to right: a 9.21 carat (ct) colorless emerald cut from Nigeria; a 15.01 ct light blue emerald cut from Brazil; an 18.41 ct purplish pink emerald cut from Pakistan; and a 12.54 ct orange-red emerald cut from Brazil. Photo: Robert Weldon/GIA

Color varieties of the November birthstone are often identified simply by hue name—blue topaz, pink topaz and so forth—but there are also a couple of special trade names. Imperial topaz is typically a medium reddish orange to orange-red though some dealers, especially those in Brazil, apply the term to yellow, pink and red topaz as well. The reddish pleochroic color (pleochroism is the display of different body colors from different viewing directions) of Imperial topaz often appears at the ends of fashioned gems–like pears and ovals–that have an otherwise yellow-to-orange body color. Red is one of the most sought-after (and least available) topaz colors.

Sherry topaz—named after sherry wine—is a yellowish brown or brownish yellow to orange. Stones in this color range are often called precious topaz to help distinguish them from the similarly colored but less expensive citrine and smoky quartz.

Topaz is an 8 on the Mohs Scale of Hardness. It’s not very tough, so a hard blow might split it, and extreme pressure or sharp temperature changes might cause it to break. The November birthstone is best set in a protective mounting like a bezel or used in pieces that aren’t subjected to heavy wear, like pendants and pins.

Pink topaz set in a diamond and platinum butterfly brooch.

A pink topaz set in a diamond and platinum butterfly brooch is a delightful sight. Photo: Robert Weldon/GIA. Courtesy: Richard Krementz Gemstones

Gemologists love topaz because it comes in some of the gem world’s largest crystals: The largest are measured in kilos, not carats. They also love the fact that faceted topaz takes such a high polish and is slightly slippery to the touch.

November birthstone: Topaz history & lore

Topaz was long thought to have many benefits. The ancient Greeks believed that topaz gave them strength. From the 1300s to the 1600s, Europeans thought it could thwart magic spells and dispel anger. The November birthstone was also believed to have curative powers. To treat “dimness of vision,” 12th century abbess St. Hildegard recommended placing topaz in wine for three days and then rubbing the moistened topaz on the patient’s eyes.

Imperial topaz has aristocratic cachet. It is commonly believed that the name originated with the Russian royal family’s insistence on keeping the finest colors of this gem, which was mined in Russia’s Ural Mountains, exclusively for their use. An alternate explanation, especially popular in Brazil, is that it dates from an 1881 visit by Brazilian Emperor Pedro II to Ouro Preto—the town closest to Brazil’s most productive topaz mines–and the gift of a reddish topaz to him. Regardless of the source of the designation, there is no question all believed this beautiful gem was fit for a king.

Oval cut Imperial topaz.

Want a gem with an aristocratic cachet? Imperial topaz might be the one for you. Photo: Robert Weldon/GIA

Blue topaz is the gem of the fourth wedding anniversary, and Imperial topaz is the gem of the 23rd wedding anniversary.

A 38.56 ct blue topaz

The artistic carving of this 38.56 ct blue topaz intensifies the color. Photo: Lydia Dyer. Courtesy: John Dyer & Co.

November birthstone: Where topaz comes from

Minas Gerais, a state in Brazil, is one of the most important sources for high-quality topaz. Yellow to orange, red, pink, violet and blends of red with orange or purple are some of the colors unearthed here. The nearby town of Ouro Preto is a fitting companion. In this UNESCO world heritage site, majestic colonial churches checker the skyline and quaint cobblestone streets crisscross the city.

Necklace set with a 24.13 ct fancy-cut topaz and the accompanying 44.11, 71.21 and 66.66 ct loose stones.

Topaz mined from the Ouro Preto region of Minas Gerais, Brazil comes in a lovely range of hues, as displayed in this necklace set with a 24.13 ct fancy-cut topaz and the accompanying 44.11, 71.21 and 66.66 ct loose stones. Photo: GIA and Harold & Erica Van Pelt. Courtesy: Amsterdam Sauer Co.

Northwestern Pakistan is known for producing pink topaz. Ghundao Hill, close to the small town of Katlang, has been mined since 1972. The most sought-after shade of pink topaz from Katlang has a tinge of violet, which some in the gem trade call cyclamen pink. But even at Ghundao Hill, only rarely is fine pink topaz found.

Ghundao Hill, a valley carpeted in green in Northwestern Pakistan, is known for producing topaz the November birthstone.

Ghundao Hill’s setting is quite picturesque: A valley carpeted in green starts at the base. The towering Hindu Kush Mountains rise in the distance. Photo: Dr. Edward J. Gübelin/GIA

Other topaz sources include Namibia, on the western coast of southern Africa, and the gem-rich island of Madagascar. Today, some topaz is also found in the historic Russian localities and elsewhere including, Africa, China, India, Myanmar, Sri Lanka and Vietnam, as well as the United States and Mexico.

November birthstone: Qualities to look for in topaz

Color: Blue topaz and colorless topaz are widely available and very affordable. Most of the blue topaz on the market today has been color treated, as described in the next section. Red and pink topaz varieties are rare, highly cherished and will carry a significantly higher price tag per carat. Imperial topaz is also highly prized.

An 11.11 ct Imperial topaz ring accented with 0.29 carats of rubies and 0.75 carats of diamonds, all set in rose gold.

A royal enchantment: This 11.11 ct Imperial topaz is accented with 0.29 carats of rubies and 0.75 carats of diamonds, all set in rose gold. Courtesy: Omi Privé

Clarity: Faceted blue topaz is almost always free of eye-visible inclusions. Topaz in colors that are not as plentiful may be included. Depending on the rarity of the color, inclusions may not have a significant effect on value.

Cut: Topaz is cut in a wide variety of shapes and styles, including emerald, cushion, oval, pear, round, triangular, marquise and fantasy cuts.

Carat weight: If the color of the topaz is considered rare, the per-carat price may rise dramatically as size increases.

A 1,002 ct fantasy cut topaz

This 1,002 ct fantasy cut topaz is a work of art. Photo: Orasa Weldon/GIA

November birthstone: Topaz treatments, care & cleaning

To clean this November birthstone, do not use steam cleaning or ultrasonic cleaners to clean topaz: Warm, soapy water works best.

Topaz is often treated. Since naturally colored blue topaz is extremely rare, colorless topaz is often processed with irradiation followed, in some cases, by heating to turn it various shades of blue. The three irradiation techniques used are exposure to gamma rays in a cobalt irradiator, bombardment with electrons in an accelerator and bombardment with neutrons in a nuclear reactor. Gems that are treated in an accelerator or nuclear reactor may become radioactive, but the U.S. National Regulatory Commission (NRC) does not allow release of such stones into the trade until radioactivity levels fall below certain limits. The NRC advises that “any dose from these gems would be extremely small” and would continue to go down. Dealers use terms like “London blue,” “Swiss blue,” “super blue” and “maxi blue” to describe darker blues, and “sky blue” for paler hues. In general, darker blues cost slightly more than lighter hues, but both are typically affordable.

A blue topaz that has undergone irradiation to achieve a color result often referred to as “Mystic Topaz” or “Caribbean Topaz”.

This blue topaz has undergone irradiation to achieve this color result often referred to as “Mystic Topaz” or “Caribbean Topaz” by the trade. Photo: Valerie Power/GIA

Also common, is the heating of yellow to reddish brown topaz to create pink gems. Both irradiation and heat treatment are permanent under normal conditions of wear and care. For the most part, they are undetectable.

High heat or sudden temperature changes can cause internal breaks in topaz. The gem’s color is generally stable to light, but prolonged exposure to heat or sunlight might cause fading in yellow-to-brown, reddish brown or dark brown gems. Topaz may be affected slightly by some chemicals.

In addition to irradiation and heat treatment, colorless topaz is sometimes coated with a thin metallic film to change the color or produce a fanciful iridescent effect. The coating can resist daily wear and tear, but abrasive cleaners or buffing wheels will remove it. Only a mild soap solution should be used to clean a topaz treated in this manner.

November birthstone: Gemological properties of citrine

Citrine is the transparent pale yellow to brownish orange variety of quartz. The finest citrine color is a saturated yellow to reddish orange free of brownish tints. Its color comes from traces of iron. However, this November birthstone is actually rare in nature: Most citrine on the market is the result of heat treating amethyst.

Citrine’s attractive color, plus the durability and affordability it shares with most other quartzes, makes it the top-selling yellow-to-orange gem. Gemologists love this November birthstone because it has a modest price tag, and the price per carat does not rise dramatically for larger sizes.

The Jolie Citrine Necklace features 64 graduated bezel-set cushion cut citrines, highlighted by a 177.11 ct pear shaped citrine drop.

The Jolie Citrine Necklace, once owned by American actress Angelina Jolie and now part of the National Gem Collection at the Smithsonian Institution, features 64 graduated bezel-set cushion cut citrines, highlighted by a 177.11 ct pear shaped citrine drop. Courtesy: RP Studio

November birthstone: Citrine history & lore

This November birthstone is a variety of quartz, which has been used in jewelry for thousands of years. The ancient Greeks carved rock crystal ornaments that glistened like permafrost. Roman pontiffs wore rings set with massive purple amethysts and citrine has been reported in Roman jewelry. It was particularly popular in colorful Scottish jewelry from the Victorian era. Citrine, believed to derive from the French word for lemon (citron), is given for the thirteenth wedding anniversary.

A 43.49 ct fantasy cut citrine.

A fantasy cut unleashes the fire within this 43.49 ct citrine. Photo: Priscilla Dyer. Courtesy: John Dyer & Co.

November birthstone: Where citrine comes from

The top sources for natural citrine are Bolivia, Spain, Madagascar, Mexico and Uruguay. Amethyst that’s typically heat treated to a citrine color is mined mostly in Brazil.

Citrine and diamond butterfly earrings

These citrine and diamond butterfly earrings remind us of the beauty surrounding the Anahí mine in Bolivia. Photo: C. D. Mengason/GIA. Gift of Denoir

Deep in the world’s largest freshwater wetland lies Bolivia’s Anahí mine, an important source for natural, unheated citrine. Fields of wild flowers, brightly plumed birds, kaleidoscopes of butterflies, Howler monkeys and jaguars are some of the actors on this vast stage. The story of the mine is worthy of the setting. Discovered by a Spanish conquistador in the 1600s, it was given to him as dowry when he married Anahí, a princess from the Ayoreos tribe of Paraguay. The mine was lost for three centuries, until it was rediscovered in the 1960s.

The Anahí mine in Bolivia, an important source for the November birthstone citrine.

Cradled between the two mountains lies the Anahí mine in Bolivia. Photo: Robert Weldon/GIA

The Anahí mine produces a unique combination of amethyst and citrine in the same crystal; when the two colors appear together in a fashioned gem, it is known as ametrine. The citrine produced at the Anahí mine typically ranges from orange-yellow to brownish/greenish yellow.

Citrine, amethyst and ametrine gems produced at the Anahí mine in Bolivia.

The Anahí mine produces citrine, amethyst and ametrine gems in a broad range of hues. Photo: GIA & Tino Hammid

November birthstone: Qualities to look for in citrine

  • Color: The finest citrine colors are saturated, with little to no brown component, and range from yellow to orange-yellow to reddish orange. Look for warm, sunny hues.
  • Clarity: Citrine is usually “eye clean,” meaning it lacks eye-visible inclusions. Visible inclusions in a pale-colored gem greatly reduce the citrine’s value.
  • Cut: Citrine is available in a wide variety of standard shapes and cutting styles. In addition, many high-end gem carvers have fashioned the warm yellow gem into unusual fantasy cuts for distinctive jewelry and objets d’art. Citrine rough with minor inclusions is often used to make beads or is used occasionally for cabochons or more conventional carvings.
  • Carat weight: Citrine crystals occur in a wide range of sizes, and faceted stones up to 20 carats are readily available in jewelry.
A citrine and diamond ring set in 18K gold.

Like an ember, citrine glows in this ring. Courtesy: Arya Esha

November birthstone: Citrine treatments, care & cleaning

Citrine can be safely cleaned with warm, soapy water. While it is usually okay to clean citrine in an ultrasonic machine, steam cleaning is risky since citrine should not be subjected to heat.

As noted above, most of the citrine on the market is the result of heat treatment, which causes some amethyst to change color from an undesirable pale violet to an attractive yellow. In some cases, a darker starting material is used, as the amethyst’s original hue can determine the richness of the resulting citrine’s yellow color.

A 15 ct citrine pendant encircled by 0.30 carats of diamonds.

Spring Bouquet, a pendant made for Rio Tinto’s “Diamonds with a Story” marketing campaign, glows with a 15 ct citrine encircled by 0.30 carats of diamonds. Courtesy: Matthew Campbell Laurenza

Love topaz? Craving citrine? You’ll find our Topaz Buying Guide and Citrine Buying Guide to be extremely helpful.

Read More
Read More
Rose gold oval diamond engagement ring
Diamond Engagement Ring Setting: How Metal Affects Diamond Color Appearance

Selecting the right metal for your engagement ring setting is just as important as selecting the right diamond. The metal will not only define the ring’s style, but it can also play a big role in your diamond’s color appearance. Here’s how to choose wisely.

A solitaire center stone surrounded by diamond melee in a gold engagement ring setting.

A gold engagement ring allows the solitaire diamond to be the star of the show. Diamond melee along the ring’s shank play a supporting role, adding even more sparkle to the overall effect. Courtesy: Stuller Inc.

Gold, platinum and silver are the metals most often used in jewelry. Their allure, workability and durability make gold and platinum excellent choices for an engagement ring. For many people, choosing an engagement ring setting starts with a color and style preference. Some prefer the warmth of yellow gold or rose gold engagement rings; others opt for the coolness and classicism of white metals such as platinum or white gold for their engagement rings. Yet few people consider the effect that engagement ring’s metal color has on the most important feature of an engagement ring – the center stone, which is often a diamond.

A 5.31 carat (ct) oval diamond set in a rose gold engagement ring setting.

An 18K rose gold band brings warmth to this 5.31 carat (ct) oval diamond. Courtesy: Rahaminov Diamonds

The importance of diamond color and reflection

When choosing an engagement ring setting in white gold, rose gold, yellow gold, platinum or silver, consider these important things:

Your diamond’s color. Although many people think of gem-quality diamonds as colorless, truly colorless diamonds are actually very rare. Most diamonds used in jewelry and diamond engagement rings are nearly colorless with hints of yellow, brown or gray. In picking an engagement ring in yellow gold, white gold or other metal for your ring setting, you’ll need to know where your diamond is on the GIA D-to-Z Color Scale.

The fact that diamonds are highly reflective. The many facets of a standard round brilliant diamond and other diamond shapes act like tiny mirrors reflecting their surroundings, including the color of the band and the prongs holding the gem.

Knowing this, you can use the color of the metal in your engagement ring to highlight your diamond’s color or create a more harmonious appearance.

A 1.20 ct emerald cut diamond set in an 18K gold engagement ring setting.

An 18K gold band complements the hint of yellow in this 1.20 ct N color emerald cut diamond for a very harmonious look. Courtesy: 1stdibs.com

Once you’ve settled on whether you want your engagement ring design to highlight the main diamond or create a sense of harmony between the setting and the center stone, you’ll have many options to choose from. Remember, your jeweler is your best resource. She or he will understand the subtle nuances of diamond color and can make the best metal color recommendations to achieve the look you’re going for. Also, the best way to see a metal’s effect on diamond color appearance is to see the diamond and the engagement ring setting in person. In the meantime, though, here are some tried and true ideas to get you thinking.

Metals for diamonds graded D through J

All things being equal for diamonds on the D-to-Z scale, the less color the stone has the more valuable it is. Diamonds graded D-E-F on the GIA color scale are considered colorless, and a white metal—platinum or white-gold engagement ring setting is the ideal choice to emphasize their beauty. Diamonds graded G through J are in the near-colorless range, with an almost imperceptible hint of yellow. They, too, are good candidates for a platinum or white gold ring setting.

If you choose another color of metal or opt for a two-tone ring to create contrast, the prongs that hold the diamond should be a white metal like white gold or platinum. Yellow gold prongs could impart some yellow color to the diamond, making your colorless or near-colorless stone look like it has a different color grade.

A 8.03 ct D color marquise diamond with 0.72 carats of colorless baguettes set in a platinum engagement ring setting.

A platinum band heightens the icy beauty of this 8.03 ct D color marquise diamond with 0.72 carats of colorless baguettes. Courtesy: 1stdibs.com

This diamond ring features white diamond melee in an 18K rose gold halo engagement ring setting.

Like the white look, but want some contrast? This diamond ring features white diamond melee in an 18K rose gold halo, which adds visual richness to the design. Courtesy: PE Jay Creations

Metals for diamonds graded M through Z

A diamond with a color grade of M or lower will likely have a noticeable yellow tint. A yellow gold band will accentuate the yellow in the diamond; a white band might make the diamond appear more colorless. Diamonds with a color grade of K or L are in something of a middle zone; you can use either yellow gold or white metal bands such as platinum or white gold, depending on the effect you want for your engagement ring setting.

A K color diamond in a gold engagement ring setting.

The diamond center stone in this ring is a K color. A gold band brings out the hint of yellow, giving the diamond a softer appearance. Courtesy: TrueFacet.com

Set in a platinum engagement ring setting, this 11.04 ct yellowish diamond is surrounded by 5.05 carats of white diamond melee.

A fanciful platinum setting with 5.05 carats of white diamond melee provides a pleasing contrast with the 11.04 ct yellowish diamond center stone. Photo: Robert Weldon/GIA. Courtesy: MUNNU The Gem Palace

Picking metals for fancy-color diamonds

Diamonds that fall outside the D-to-Z color range are called “fancy colors.” Selecting the right metal to accentuate these unique stones is key to delivering the radiance and allure of each engagement ring. Naturally occurring colors include blue, brown, pink, yellow and green. These diamonds are evaluated less for brilliance or fire and more for color intensity. Depending on the hue, tone and saturation of the color, the GIA Colored Diamond Color Grading System assigns colored diamonds one of these color grades: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark and Fancy Deep. Generally, Fancy Vivid and Fancy Deep command the highest prices.

Metals for brown diamonds

Brown diamonds were once deemed unsuitable for jewelry. Then marketers in the 1980s gave them tantalizing names like champagne, cognac and chocolate, and brown diamonds developed their own niche.

Like yellowish diamonds, brown diamonds can be placed on a white gold or platinum engagement ring setting to highlight their color, or they can be placed in a yellow gold or rose gold engagement ring setting to complement their color. Even the metal used for prongs can either contrast or complement the diamond in the center.

A 0.38 ct brown diamond in an 18K white gold engagement ring setting, surrounded by a double halo of white diamond melee.

A 0.38 ct brown diamond pops because it is set in an 18K white gold band and surrounded by a double halo of 0.39 carats of white diamond melee. White prongs accentuate the look. Courtesy: 1stdibs.com

A yellow gold engagement ring setting featuring a brown cushion cut diamond accented with platinum prongs and white diamond side stones.

Neil Lane designed this ring for actress, model and Paralympic medalist Amy Purdy. A brown cushion cut diamond is the center stone. A yellow gold band creates a soft backdrop, while platinum prongs and white diamond side stones provide an arresting contrast. Courtesy: Neil Lane

Metals for yellow diamonds

Yellow diamonds were relatively rare until the discovery in the late 1860s of quantities of what today would be considered fancy yellows at several locations in South Africa. They are now found around the world. The presence of nitrogen gives them their color.

A platinum or white gold engagement ring can highlight the color of a yellow diamond, while a yellow gold ring will harmonize with the color of the yellow diamond.

A double halo engagement ring setting of 0.94 carats of white diamonds is the backdrop for a 1.02 ct yellow diamond

A double halo of 0.94 carats of white diamonds is the frosty backdrop for a 1.02 ct yellow diamond. Courtesy: 1stdibs.com

A 7.02 ct fancy yellow heart shaped diamond with 1.08 carats if yellow diamonds in the halo and shank in an 18K gold engagement ring setting.

The combination of a 7.02 ct fancy yellow heart shaped diamond, 1.08 carats of yellow diamonds in the halo and along the shank and an 18K yellow gold band creates an enchanting engagement ring setting. Courtesy: Norman Silverman

Metals for pink diamonds

Pink diamonds are exceedingly rare. Historically, they have been found in Brazil’s alluvial workings and in Indian and African mines. Since the late 1980s, the Argyle mine in Australia has been the most important source of pink diamonds, but even here they are quite rare. According to Rio Tinto Ltd., the owner of the mine, “more than 800 million carats of rough diamonds have been produced from the Argyle Diamond Mine. Total carats of pink rough: less than 1% of total production.” Not surprisingly, pink diamonds are extremely expensive.

Since the color of pink diamonds is so prized, it is rare to see them set in a yellow gold engagement ring setting. A pink diamond is the star, and the white metal band is used to highlight its color.

A white metal engagement ring setting and double halo of white diamonds surround a 16.08 ct Fancy Vivid pink diamond.

A white metal band and double halo of white diamonds form the elegant frame for this 16.08 ct Fancy Vivid pink diamond. The piece sold for more than $28.5 million at a Christie’s auction in November 2015. Courtesy: Christie’s

Metals for blue diamonds

Blue diamonds are also extraordinarily rare and very expensive. India is their historic source, and it is believed that the 45.52 ct Hope Diamond, the 31.06 ct Wittelsbach-Graff and other famous blue diamonds originated there. Today, the Premier mine in South Africa, which opened in 1903, is considered the most significant source of blue diamonds. Nevertheless, at the end of the 20th century blue diamonds accounted for less than 0.1% of diamonds found there.

Like pink diamonds, they are almost always set in a platinum, white gold or silver engagement ring setting that highlights their color.

A 5.98 ct Fancy light blue diamond in a platinum engagement ring setting.

A natural 5.98 ct Fancy Light blue diamond sits in a platinum band. Courtesy: Royal Ontario Museum, Toronto, Canada; Gift of Vincent Tovell. Certified by the Canadian Cultural Property Export Review Board under the terms of the Cultural Property Export and Import Act.

A beautiful engagement ring is the product of a number of choices that add up to a stunning creation. Knowing how to protect your diamond engagement ring setting is another important consideration.

Read More
Read More
Pear Shaped 5.76ct Morganite
How to Pick a Morganite Engagement Ring

Morganite engagement rings are trending – and for good reason. Morganite is a beautiful, durable and a comparatively affordable pink gem. It has also benefited from a lot of buzz. Here’s what you need to know about morganite engagement rings.

In this blog, we’ll cover:
Why is morganite so popular?
What type of gem is morganite?
Where does morganite come from?
Morganite qualities to look for
Adding diamonds to a morganite engagement ring
Setting ideas for morganite engagement rings
Caring for and cleaning a morganite engagement ring

Why is morganite so popular?

4.08 carat (ct) center stone encircled by diamonds that trail down the shank. The 18K rose gold setting accentuates the morganite’s color.

Morganite is a picture of romance in this ring featuring a 4.08 carat (ct) center stone encircled by diamonds that trail down the shank. The 18K rose gold setting accentuates the morganite’s color. Courtesy: 1stdibs.com

Interest in morganite engagement rings may have started in 2002, when Ben Affleck proposed to Jennifer Lopez with a 6.1 carat (ct) pink diamond. Pink picked up more momentum when Apple introduced its now iconic rose gold iPhone in 2013 and Pantone named “Marsala” — an earthy red hue that morganite compliments beautifully — the 2015 Color of the Year.

Fashion trends aside, pink has long been associated with love, romance, femininity and tenderness – so it’s not surprising that pink gems have an irresistible appeal. The color pink also flatters any skin tone.

The affordability of morganite engagement rings – especially compared to pink diamonds – puts the look within reach of brides-to-be. It is easy to see why morganite engagement rings, especially those with rose gold settings, have become so popular.

What type of gem is morganite?

20.03 ct morganite ring. Decorating the halo and band are 1.07 carats of diamonds.

All that seems to be missing from this 20.03 ct morganite ring is the bride who will wear it. Decorating the halo and band are 1.07 carats of diamonds. Courtesy: 1stdibs.com

Morganite is a delicate pastel pink to purplish pink (“rose”), yellowish pink (“peach”) or orangey pink (“salmon”) variety of beryl, a mineral species that also includes emerald, aquamarine and beryls in other colors. Its color is caused by traces of manganese. Strong hues in morganite are rare, and gems usually have to be fairly large to achieve the finest color.

Morganite is a 7.5 to 8 on the Mohs scale of hardness. This makes a morganite engagement ring suitable for everyday wear, although it is not as durable as harder gems like diamond or ruby and sapphire.

A fun piece of lore: Morganite was named to honor American financier and gem enthusiast J. P. Morgan (1837–1913). George Kunz, then Tiffany’s colored stone specialist and a noted gem scholar, proposed the name in 1910 after examining early samples of the beautiful pink beryl from Madagascar.

A 5.94 ct morganite is the star of this ring set in 14K rose gold with 0.70 carats of round brilliant cut diamonds.

A 5.94 ct morganite is the star of this ring set in 14K rose gold with 0.70 carats of round brilliant cut diamonds. Courtesy: 1stdibs.com

Where does morganite come from?

It takes the skilled hands of a lapidary to turn a piece of morganite rough into a gem fit for an engagement ring.

It takes the skilled hands of a lapidary to turn a piece of morganite rough into a gem fit for a morganite engagement ring. Photo: Robert Weldon/GIA. Gift of Dave Wilber

Most of the morganite on the market today comes from Minas Gerais, Brazil. Minas Gerais is a gemological treasure chest: emerald, aquamarine, tourmaline, alexandrite, amethyst and topaz are some of the other gems found there.

Afghanistan, Pakistan, Mozambique, Namibia and the United States are also sources of morganite, but for the most part, production is minor and inconsistent. While it is no longer a major producer today, the original Madagascar deposit still sets the standard for the best material.

Morganite qualities to look for

It’s easy to fall in love with this charming morganite engagement ring. It features a 1.69 ct morganite and 0.08 carats of diamonds decorating the shank.

It’s easy to fall in love with this charming morganite engagement ring. It features a 1.69 ct morganite and 0.08 carats of diamonds decorating the shank. Courtesy: 1stdibs.com

As you shop for a morganite engagement ring, keep in mind these tips for picking the perfect gem.

Color: The most prized morganite colors are strong pink, often the result of heat treatment. Untreated material, especially from Brazil, may be a salmon-like orangy pink. Morganite’s color is often pale, increasing in intensity with the size of the stone. Darker colors are usually more desired and thus cost more.

Morganite is almost always heat treated to improve its pink color. Heat drives off the yellow or orange tinge, leaving a purer and more attractive pink. The treatment is not detectable, and the resulting color is stable and won’t fade unless exposed to temperatures over 400°C.

This 10 ct oval morganite makes quite a fashion statement set horizontally in the trendy east-to-west style. The 18K rose gold setting includes four diamond accents in the prongs.

Morganite is often found in large sizes and cut into a variety of shapes. This 10 ct oval morganite makes quite a fashion statement set horizontally in the trendy east-to-west style. The 18K rose gold setting includes four diamond accents in the prongs. Courtesy: 1stdibs.com

Clarity: Faceted morganite often does not have eye-visible inclusions, though they are more likely to be present in larger sizes. Stones with numerous eye-visible inclusions are usually carved or cut as cabochons. Liquid inclusions (liquid trapped in what were once voids in the gem) and fractures are two types of internal features that might be visible to the naked eye.  Liquid inclusions tend to have irregular shapes. A fracture looks like a bright, shiny flat surface. It’s worth mentioning again that faceted morganite usually does not have eye-visible inclusions.

Cut: The shape of a morganite gem should have minimal effect on its beauty. Like a diamond, a morganite engagement ring can be attractive as a round brilliant, emerald cut, marquise or oval. Light-color material might be cut slightly deep to help intensify the color. Morganite is a popular material for unique fantasy cuts and carvings.

Carat weight: Although available (and affordable) in large stones, morganite is often cut in calibrated sizes to fit common jewelry mountings.

A solitaire is said to symbolize love, commitment and fidelity. This round morganite solitare set in rose gold brings the power of pink to a traditional engagement ring style.

A solitaire is said to symbolize love, commitment and fidelity. This round morganite solitaire set in rose gold brings the power of pink to a traditional engagement ring style. Courtesy: 1stdibs.com

Pear shaped stones help give fingers a longer, slimmer look, and this 5.76 ct morganite ring is sure to flatter almost any hand. The delicate halo of diamonds totaling 0.58 carats adds to its feminine feel.

Pear shaped stones help give fingers a longer, slimmer look, and this 5.76 ct morganite ring is sure to flatter almost any hand. The delicate halo of diamonds totaling 0.58 carats adds to its feminine feel. Courtesy: TrueFacet.com

Adding diamonds to a morganite engagement ring

A romantic pairing: A 6.40 ct morganite with 2.45 carats of diamonds that form a halo and cascade down the shank as an enchanting counterpoint.

A romantic pairing: A 6.40 ct morganite with 2.45 carats of diamonds that form a halo and cascade down the shank as an enchanting counterpoint. Courtesy: 1stdibs.com

Now that you know what to look for when picking a beautiful morganite gemstone for your engagement ring, you might want to add a bit of drama to it. Morganite and diamonds form an elegant combination. The brilliance of the diamonds creates a dramatic contrast to the subtle blush of the morganite. Diamonds in a halo setting or flanking morganite as side stones are two can’t-fail choices. Here are a few things to keep in mind when selecting diamonds for your morganite engagement ring:

  • The diamonds will probably reflect some of the pink of the morganite, so they may end up with a pinkish appearance.
  • Diamonds that have a hint of yellow will probably complement the morganite, making for a softer look.
  • Diamonds that are more colorless will contrast with the morganite, making for a bolder look.
Placing a diamond on either side of the central gem is another way to add diamonds to a morganite engagement ring. Here, an 8.68 ct morganite is framed by two pear shaped diamonds weighing a total of 0.40 carats.

Placing a diamond on either side of the central gem is another way to add diamonds to a morganite engagement ring. Here, an 8.68 ct morganite is framed by two pear shaped diamonds weighing a total of 0.40 carats. Courtesy: 1stdibs.com

Setting ideas for morganite engagement rings

Morganite works well in virtually all popular engagement ring setting styles. It’s stately enough to hold its own as a solitaire. It looks glorious with a halo (a ring of smaller diamonds placed around the center stone). And it is artfully framed and protected in a bezel setting (a jewelry setting style in which a thin metal strip is pushed or hammered around a gem to hold it in place).

Since morganite is a 7.5 to 8 on the Mohs scale of hardness, it is more vulnerable to chipping and breakage than a harder gem like a diamond. Because of this, you’ll want to put it in a setting that affords more protection. A bezel setting is an excellent choice, as the metal surrounding the morganite protects the gem from damage. Four- and six-prong settings are also common, but they offer less protection and aren’t an ideal choice for physically active individuals. All options considered, a bezel setting is the safest choice.

6.19 ct morganite surrounded by 18K rose gold and 0.22 carats of diamonds.

An antique frame cradling a magical mirror is a poetic description for this 6.19 ct morganite surrounded by 18K rose gold and 0.22 carats of diamonds. The rose gold setting not only protects the gemstone, but is also reflected in it, adding even more depth to the morganite’s pink hue. Courtesy: 1stdibs.com

If you’re looking for an engagement ring setting to complement morganite, consider the metal color and the overall look you’re trying to achieve. For a soft color palette, a rose gold band and prongs will enhance the gem’s pink hues, while yellow gold will bring out any yellow in the stone. Or you can opt to go bolder, by using white metal prongs or band (or both) to contrast with the morganite.

Consider the metal when choosing a setting for your morganite ring. You can use yellow gold to your advantage to bring out the yellow hues in some morganite, as in this morganite and diamond ring.

Consider the metal when choosing a setting for your morganite ring. You can use yellow gold to your advantage to bring out the yellow hues in some morganite, as in this morganite and diamond ring. Courtesy: Denise James

Caring for and cleaning a morganite engagement ring

Warm, soapy water is always a safe cleaning method for a morganite engagement ring. Cleaning by ultrasonic and steam cleaners is also usually safe, unless the stone has liquid inclusions or fractures. Rarely, morganite is fracture filled – a glass-like substance is used to fill a fracture to make it less visible and to improve the stone’s apparent clarity. These stones should only be cleaned with warm, soapy water.

A morganite engagement ring can be damaged by some acids, including those found in certain cleaning products. Morganite is safe to wear during most everyday activities. However, like all other gemstones, morganite can be damaged, so we recommend that you remove your ring before gardening, cleaning, playing sports or participating in other strenuous activities.

This 12.18 ct pear shaped morganite is framed by a halo of 1.06 carats of pavé diamonds.

This 12.18 ct pear shaped morganite is framed by a halo of 1.06 carats of pavé diamonds. The white metal setting creates a strong contrast with the gem’s pink hue, making the morganite the star of the show. Courtesy: 1stdibs.com

Morganite in an engagement ring is sweet, romantic and trendy. It is also a charming choice – an eye-pleasing look that evokes the splendor of love.

Loretta Castoro’s “Love Doves” ring has a 2 ct round morganite accented with diamonds in the shank.

Ready for romance? Loretta Castoro’s “Love Doves” ring has a 2 ct round morganite accented with diamonds in the shank. Courtesy: Loretta Castoro Signature Collection

Now that you’re well into your search for a center stone, learn how to select flattering engagement ring styles.

Read More
Read More
Round brilliant cut diamond, 2.78 ct, D, IF.
The History of the 4Cs of Diamond Quality

The term 4Cs we know today had its start in the early 1940s, as the brainchild of GIA founder Robert M. Shipley. A former retail jeweler, Shipley was fiercely committed to professionalizing the American jewelry industry. He established an institute (GIA) to provide jewelers with formal training and was a tireless advocate for greater knowledge, ethics and standards when it came to buying and selling gems.

Robert M. Shipley, GIA Founder.

Robert M. Shipley founded the Gemological Institute of America in 1931. Photo: GIA

Shipley developed the 4Cs as a mnemonic device to help his students remember the four factors that characterize a faceted diamond: color, clarity, cut and carat weight. The concept was simple, but revolutionary.

Throughout history, diamond merchants used a variety of different, usually broad, terms to talk about these four factors, rarely with any consistency. Terms such as river or water were used to describe diamonds that were the most colorless, with Cape assigned to pale yellow diamonds from South Africa’s Cape of Good Hope region. To describe clarity, they referred to diamonds as being “without flaws” or “with imperfections.” Cut was described as “made well” or “made poorly.” As a result, it was very difficult for jewelers to communicate those elements of value to their customers or for their customers to remember them. Only the term carat to describe weight has been used consistently from the 1500s to today.

Under Shipley’s direction, the term 4Cs became part of the American gem industry’s vernacular, popularized through advertising campaigns, lectures and GIA education courses. Within decades, they were integrated into the international nomenclature as well.

The 4Cs and the Diamond Grading Scales

Jewelers welcomed Shipley’s innovation, but GIA did not stop there. Shipley’s successor as president, Richard T. Liddicoat (affectionately known as “RTL” by later generations of GIA staff) – along with colleagues Lester Benson, Joseph Phillips, Robert Crowningshield and Bert Krashes – expanded on the 4Cs.

Richard T. Liddicoat, president of GIA from 1952 to 1983.

Richard T. Liddicoat, president of GIA from 1952 to 1983, integrated the 4Cs into GIA’s curriculum and laboratory reports. Courtesy: Norman B. Samuels Portrait Photographers, Los Angeles

Their work included not only development of the now famous GIA D-to-Z Color Scale and GIA Clarity Scale for diamonds, but also the scientific methods and procedures for objectively grading a diamond’s quality.

2.78 carat (ct) D-color round brilliant diamond that is internally flawless.

A 2.78 carat (ct) D-color round brilliant diamond that is internally flawless is a wonder of nature. GIA invented the color- and clarity-grading terminology that is now used internationally to describe diamond quality. Photo: Robert Weldon/GIA. Courtesy: Rogel & Co. Inc.

Color: The GIA D-to-Z Color Scale

Before the 4Cs and RTL’s contributions, a confusing alphabet soup was used to describe a diamond’s color. In communicating color quality to consumers, retailers used competing systems with descriptors like “A,” “AA” and “AAA.” There was virtually no agreement among firms as to what was considered an “A” grade. Most diamond wholesalers used terms like rarest white and top Wesselton, in addition to those mentioned above. In short, there were no standards that allowed for consistent evaluation and comparison.

Since the 1930s, GIA had been working on an accurate, objective color-grading system for colorless to light yellow diamonds. The goal was to develop a system based on absolutes, instead of relative terms and vague descriptions. In 1953, GIA, under RTL’s direction, introduced the GIA D-to-Z color scale, choosing the letter “D” for the top grade (colorless) precisely because the letter had negative associations and so was unlikely to be misinterpreted or misused.

GIA's D-to-Z Color Scale is the industry standard for grading the color of colorless to light yellow diamonds.

GIA’s D-to-Z Color Scale is the industry standard for grading the color of colorless to light yellow diamonds.

In addition to establishing a color scale, RTL and his colleagues defined the methods that would be used to grade a diamond’s color accurately and consistently. These included determining the type of lighting and neutral background with which a diamond should be evaluated, prescribing precisely how the diamond should be held and viewed, and developing master stones: sets of diamonds of predetermined color value against which the subject diamond is carefully compared.

The D-to-Z diamond color terminology RTL and his colleagues pioneered is now used around the world, and strict color-grading procedures are followed by the GIA laboratory.

This engagement ring has a 1 ct center stone surrounded by four diamond side stones. Melee diamonds in a halo setting frame the design and continue down the shoulders of the ring.

Understanding the 4Cs is essential if you’re shopping for a diamond engagement ring. This one has a 1 ct center stone surrounded by four diamond side stones. Melee diamonds in a halo setting frame the design and continue down the shoulders of the ring. Courtesy: Sylvie Collection

The GIA Clarity Scale contains 11 grades that range from Flawless (FL) to Included (I3).

The GIA Clarity Scale contains 11 grades that range from Flawless (FL) to Included (I3).

Clarity:  The GIA Diamond Clarity Scale – Flawless to I3

Diamond clarity grading was another area that was plagued by inconsistencies in terminology and methods. Some trade professionals used terms like perfect in addition to without flaws and with imperfections, which were vague and imprecise. Others used terms we recognize today, such as VS, VVS, and included, but without any agreed-upon definitions.  RTL and Benson used these terms in creating a clarity-grading scale, but defined precise categories and expanded the number of grades within each category to account for the array of diamonds in the market. Fine-tuned in subsequent years, the GIA Clarity Scale today consists of six categories ranging from Flawless to Included and contains 11 specific grades.

This precision in clarity grading was made possible by another GIA innovation: the introduction of the gemological microscope as a tool for clarity grading. Using the microscope, GIA graders plot the inclusions and blemishes in all diamonds for which a full GIA Diamond Grading Report has been requested.

A plotting diagram, a feature of all GIA Diamond Grading Reports, uses specific symbols to map a diamond’s various inclusions and blemishes.

A plotting diagram, a feature of all GIA Diamond Grading Reports, uses specific symbols to map a diamond’s various inclusions and blemishes.

Cut: Evaluating a Diamond’s Interaction with Light

The impact of Cut – how well a diamond interacts with light – was another attribute that RTL and his associates wanted to better explain and standardize. Originally, RTL turned to the work of Belgian mathematician and diamond cutter Marcel Tolkowsky to help determine “ideal” proportions for a round brilliant cut diamond. RTL’s contribution included a rating system with deductions for proportions that deviated from those.

Because of GIA’s efforts to standardize the evaluation of diamond cut, round brilliants such as these can now be objectively graded.

Because of GIA’s efforts to standardize the evaluation of diamond cut, round brilliants such as these can now be objectively graded. Courtesy: Supreme Jewelry

GIA’s system for evaluating cut has been modified over the decades. In 2006, after years of extensive research that included advanced computer modeling and observational studies, GIA introduced the GIA cut grading system for round brilliant cut diamonds. Today, the GIA Cut Scale, ranging from Excellent to Poor, describes how successfully a diamond interacts with light to deliver the brightness, fire and scintillation we associate with a fine round brilliant.

The GIA Cut Scale assesses the overall cut quality of each diamond individually, taking into account such features as proportions, table size, polish and symmetry.

The GIA Cut Scale assesses the overall cut quality of each diamond individually, taking into account such features as proportions, table size, polish and symmetry.

Many factors contribute to the evaluation of a diamond’s cut, including the size of the facets, girdle thickness and total depth.

Many factors contribute to the evaluation of a diamond’s cut, including the size of the facets, girdle thickness and total depth.

More than the 4Cs: The World Standard

Using the latest scientific advances to establish grading standards that provide consistent, repeatable results, GIA has revolutionized the jewelry industry. With the framework provided by the 4Cs, it has transformed the way diamond quality is determined and communicated and, ultimately, how diamonds are bought and sold.

These standards are strictly followed by the GIA laboratory in its nine locations worldwide. They allow GIA to deliver objective, consistent diamond grading results anywhere in the world. It is important to note that although the terminology introduced by GIA has been adopted by other laboratories worldwide, only the GIA laboratory has the proprietary equipment and procedures to grade diamonds to these standards.

All this critical information becomes part of a GIA Diamond Grading Report. With it, you’ll know the essential facts about the diamond you’re considering.

1.37 ct H-color, VS1-clarity round brilliant in a platinum Tiffany & Co. setting.

The GIA Diamond Grading System provides a complete description of diamonds such as this 1.37 ct H-color, VS1-clarity round brilliant in a platinum Tiffany & Co. setting. Courtesy: 1stdibs.com

Why ask for a GIA Diamond Grading Report? Read more and decide for yourself.

Read More
Read More
3.50 ct black opal, emerald and diamond ring. Set in 18k yellow gold.
October Birthstone: What You Need to Know About Opal

Opal is the October birthstone – and its play-of-color is so mesmerizing that it borders on magical. From coveted black opal, to serene water opal, to blazing fire opal, there’s one for every taste. We help you find your favorite. (more…)

Read More
Read More
Related Resources
Retailer Lookup
GIA Report Check
GIA Gem Encyclopedia
GIA Laboratory Services
GIA Education
Are you a retailer?
GIA.edu
General Information
Terms of Use
Copyrights and Trademarks
Privacy Notice
Contact Us
TEST
English

|

簡体中文

|

日本語

Use of this site signifies your agreement to its terms of use.
© 2002 – 2025 Gemological Institute of America Inc. GIA is a nonprofit 501(c)(3) organization.
All rights reserved.

Use of this site signifies your agreement to its terms of use.
© 2002 – 2025 Gemological Institute of America Inc.
GIA is a nonprofit 501(c)(3) organization.
All rights reserved.