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GIA 4Cs Diamond Blog

GIA 4Cs Diamond Blog

As you’re shopping for diamonds, a diamond color chart comes in handy if you’re trying to understand the subtle color differences of D-to-Z diamonds. A simple online search for “diamond color chart” delivers a host of different graphics showing the relationship between diamond color and the respective color grade. The one thing nearly all these diamond charts have in common is that they’re derived from one standard – the GIA Color Scale.

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With Halloween creeping up on us, black diamonds seem a fitting subject.

Black diamonds, much like brown diamonds, were once outcasts in the diamond world. In the 1928 book, Diamond: A Descriptive Treatise, author J.R. Sutton noted: “Ordinary black diamond is not greatly unlike black sealing wax. Opinions differ as to its virtues as a gemstone.” And until relatively recently, this negative impression still persisted.” (more…)

If you’re thinking of buying a colored diamond, you’ll want to know if its color is natural or is the result of a treatment process. (more…)

Just a few decades ago, saying a diamond was brown was considered to be the kiss of death. These ugly ducklings of the colored diamond world were often destined for industrial use. (more…)

Colored diamonds have a special allure, and rare natural color green diamonds may be the most intriguing of them all.

The green color in a diamond is the result of exposure to radiation. The source of the radiation can be naturally occurring or performed in a laboratory. Natural radiation is the result of the diamond being exposed to radioactive uranium from rocks near the earth’s surface. Artificial irradiation is achieved in a lab using either a linear accelerator (called a linac), gamma rays or a nuclear reactor. (more…)

If you love yellow diamonds, you’re not alone. Diamond connoisseurs spend millions on these stunning gemstones. (more…)

Diamonds are prized around the world for their rarity. A gem-quality diamond is already one of the most rare items found in nature. Of all colored diamonds, one color in particular is especially rare: a predominantly red diamond.   (more…)

When does yellow become orange, and orange become red? The question may sound a bit philosophical until you tie it to colored diamonds, where slight variations in color can mean huge differences in price.

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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.

Jewelry connoisseurs have gone crazy for colored diamonds. And their appetites were practically insatiable in 2013.

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coated collections of colored diamonds

As a diamond consumer, you’ve probably heard the term “diamond treatment” or “treated diamond,” or perhaps “enhanced diamond” and wondered what that meant. A relatively small percentage of gem-quality diamonds are treated and they are treated for two reasons: to improve clarity or to alter color.

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Do you know how diamond color is evaluated? GIA kicks off its 4Cs Q&A series with color grading. (more…)

Last week, we gave a broad overview of the 4Cs. Today, we discuss how to evaluate diamond color. Did you know most diamonds are not truly colorless and contain subtle hints of yellow or brown? (more…)