Cat's Eye Moonstone Gemstone

Cat's Eye Moonstone Gemstone
[For Information and Educational purposes only]
By Alice Koh

Feldspar gemstones are classified either as potassium feldspar or plagioclase feldspar. Cat's eye moonstone is a potassium feldspar, the same as amazonite, orthoclase and sanidine.

Cat's eye moonstone is of a potassium aluminum silicate chemical formula. It occurs in a monoclinic, prismatic crystal structure. Cat's eye moonstone has a hardness ranging from 6 to 6.5 on the Mohs scale and has a perfect cleavage (which makes it a fragile gemstone.)

Cat's eye moonstone is typically translucent, though transparent specimens can be found and these are most valuable.

Cat's eye moonstone has a glass-like to pearly luster. It gives off a weak, bluish, orange fluorescence. It is usually colourless, yellow and has a pale sheen. Moonstones, however, are often found with a silvery sheen with base body colours of gray, mocha brown, yellow, orange, green, pink, blue, cream and white. The most sought after moonstones are the ones with blue sheen and white to colourless body colour. The deep-blue moonstones are the most valuable.

Cat's eye moonstone is a transparent to opaque variety of orthoclase feldspar that exibits the rare trait of chatoyancy. Chatoyancy is an optical phenomenon that closely resembles the slit-eye of a cat. It is an extremely rare phenomenon found in only few gemstones such as cat's eye chrysoberyl, apatite, aquamarine and tourmaline.

In addition to the cat's eye effect in the moonstone, it also displays the optical trait of adularescence, which is a magical, bluish-white shimmer or a wavy glowing light. This chatoyancy and adularescence in a moonstone is extremely rare. Top quality cat's eye moonstone can display the 'three-dimensional' colour of white, blue or blue-orange.

Cat's eye moonstone occurs in the same mines as moonstones. The most important deposits are sourced from Sri Lanka and India. Other notable mines are found in Australia, Brazil, Myanmar (Burma), Madagascar, Mexico, Norway, Switzerland, Tanzania and the United States.

In order to maximize the car's eye effect and adularescence in cat's eye moonstone, it is always cut en cabochon. Cat's eye moonstones are also cut with very high domes and in ovals. The most valued cut in cat's eye moonstone is the round cut that comes also in a large carat size.

Cat's eye moonstone is not known to be treated or enhanced in any way, but it has been reported that some blue coloured ones have been enhanced by 'coating.'

Moonstones have been considered sacred stones by ancient cultures and peoples. In India, it was believed that moonstones were created from the moonlight and that if you wish to see the future, you are to place a moonstone gemstone in your mouth during a full moon. In India, moonstones were believed to bring luck and good fortune. In Arab countries, moonstones were believed to make women fertile and thus they would sew a moonstone into their underwear garments.

In ancient Rome, the Romans believed that moonstones were made from drops of moonlight. and therefore they possessed properties associated with the moon such as fertility, intuition, dreams and love. Moonstones are also believed to relieve physical pains such as headaches.

Moonstone since they are soft and fragile, are perfect for protective-style jewellery designs such as earrings, pendants, pins and brooches. Cat's eye moonstone can be worn as a ring, but this ring must come in a protective setting in order to protect it from scratches and blows.

To clean your beautiful cat's eye moonstone gemstone use only a mild soap and wipe down your stone using a soft cloth. Be sure to rinse well to remove soapy residue.