Moonstone

Moonstone comes in two varieties rainbow moonstone and all the rest.

You may have seen rainbow moonstone being sold as flashy. That's labradorescence, which is caused by light reflecting from inside of the stone off what's called a twinning surface, producing a flash of color. Colors vary, including blues, greens, and yellows. More than one color can be seen when different twinning surfaces inside the gemstone reflect different colors.

But rainbow moonstone isn't really moonstone. It's a variety of labradorite from which the term labradorescence was coined.

What is moonstone then? I won't get technical other than to say that it has its own amazing feature that causes a moving floating light within the gemstone. Adularescence or schiller as it is commonly called creates a cat's eye when the band is clearly distinct and a silky luster of chatoyance when the band is indistinct.

The moonstone glow is usually white, but can also come in orange or blue. The stone itself comes in many colors, including nearly clear to white. My favorites are chocolate, peach, and gray. 

Treat moonstone gently. It's hardness rating is 6 to 6.5, but it's easy to cleave and thus susceptible to scratches and chips if not taken care of properly. Read our post on Caring for Jewelry for our recommendations.

Moonstone image copyright Didier Descouens and used under the Creative Commons Attribution-Share Alike 4.0 International license.