According to Hindu mythology, moonstone is made of moonbeams! And it’s easy to see why so many cultures also associate the gem with moonlight. Read on to learn all about this remarkable gem, including what gives moonstone its other-worldly glow.
Moonstone’s internal structure scatters light, creating a visual phenomenon known as adularescence – a light that appears to move across the gemstone, giving its surface a glowing appearance. The misty light rolls across the gem as you move it, reminding us of the full moon shining through a veil of thin, high clouds.
What is Moonstone?
Moonstone is gem-quality feldspar – a group of closely related mineral species – the most widespread minerals in the earth’s crust as well as some of the most diverse. Moonstone can be not one, but two feldspar species, orthoclase and albite. Other feldspar minerals that may also show adularescence are labradorite and sanidine (another variety of orthoclase). To be called moonstone, a mineral’s actual chemical composition is not as important as the beauty of its adularescence.
Buying Moonstones: What to Look For
The most highly favored moonstones have a colorless, semitransparent to nearly transparent appearance without visible inclusions, and a vivid blue adularescence, known in the trade as blue sheen. The finest moonstone is a gem of glassy purity with a mobile, electric blue shimmer.
Moonstone colors can vary widely: they can be white, green, yellow to brown, or gray to nearly black. In addition to blue, the adularescent effect can also be silver or white.
A good moonstone should be as free of inclusions as possible, since visible inclusions can potentially interfere with adularescence.
Moonstone might be fashioned into beads for strands, but the most common cutting style is the cabochon, a form that displays its phenomenal color, or colors, to the best advantage. Cabochon dimensions should be uniform and the profile shouldn’t be too flat, so as to emphasize moonstone’s signature sheen.
Moonstone is popular for carving into decorative jewelry elements, such as cameos or the popular “man-in-the-moon” face that plays on the gem’s name. The uneven surface of the carving combines with the shifting adularescent sheen to create a delightfully intricate and lively effect.
Moonstone comes in a wide range of sizes and carat weights. However large, fine quality moonstone is unusual.
Moonstone ranks 6.0 to 6.5 on the Mohs Hardness Scale and has poor toughness, so it is less durable than sapphire, diamond, or amethyst. It is vulnerable to scratching and also chipping or cleaving if accidentally hit against a hard surface. That’s why you’ll usually find moonstone set into pendants, earrings, and brooches. Moonstone is not typically treated, and cleaning with warm soapy water is always safe. Avoid ultrasonic or steam cleaners.
Legends say that moonstone brings good luck. And many believed that you could see the future if you held a moonstone in your mouth during a full moon. So as you gaze upon the moon and wonder what tomorrow has in store, consider acquiring a moonstone. It may not foretell the future, but you’ll carry a little bit of moonlight wherever you go.