from the AGTA website:
"The ancient Romans theorized that moonstone, with its unearthly shimmer, was formed from frozen moonlight. This appealing gem variety does shine with a cool lunar light but it is the mineral feldspar, quite terrestrial in origin. The shimmer, which is called schiller or adularescence, is caused by the intergrowth of two different types of feldspar, with different refractive indexes.
Moonstones come in a variety of colors. The body color can range from colorless to gray, brown, yellow, green, or pink. The clarity ranges from transparent to translucent. The best moonstone has a
blue sheen, perfect clarity, and a colorless body color. Another related feldspar variety is known as rainbow moonstone. In this variety, the sheen is a variety of rainbow hues, from pink to yellow,
to peach, purple, and blue.
Fine moonstone is quite rare and becoming rarer. It is mined in Sri Lanka and Southern India. The rainbow variety can be found in India and Madagascar.
Moonstones are usually cut in a smooth-domed oval cabochon shape to maximize the effect. Sometimes they are carved to show a man-in-the-moon face.
Moonstone should not be stored in contact with your other gemstones to prevent scratching. Clean with mild dish soap: use a toothbrush to scrub behind the stone where dust can collect."
Here is a link to GIA's Buyer's Guide on Moonstones:
|not really from the moon but with a galactic blue-sheen!
|colors available:||semi-transparent white
semi-transparent pale yellow
milky pale yellow
(all with a white to pale blue sheen ('floating light'))
|family/species:||feldspar-orthoclase (sometimes albite/oligoclase)|
RI=1.518 - 1.526 DR
suitable for use in jewelry
(see policy on Treatment Disclosure)
|important information||semi-transparent moonstone gems with a blue sheen ('floating light') are the most highly prized in the
moonstone has cleavage and must be handled with care, especially during cutting and polishing
|cuts:||calibrated up to 8mm
all standard cut and free size cabochons
|rough:||generally available in cabbing material to cut 8mm and under; bigger pieces occasionally available - please Contact Us for current stock|
|mining:||found in tanzania, sri lanka, myanmar (burma) and other localities|