Moonstone is a pearly and opalescent variety of orthoclase feldspar and it got its name because of the blue-white sheen caused by the lamellar structure.

Locations:

Top quality moonstone comes from Burma and Sri Lanka. Other localities are Madagascar, India, USA, Mexico, Tanzania and the European Alps.

Chemical Composition: Potassium Aluminum Silicate
Crystal Structure: Monoclinic
Hardness: 6
Specific Gravity: 2.57
Refractive Index: 1.52-1.53
Colors: Colorless, yellow, gray, pinkish orange, black and brown.
Luster: Vitreous

Astrological Relevance:

Moonstone feldspar is considered as one of the birthstones for the month of June, which covers two zodiac signs: Gemini (May 21 To June 21) and Cancer (June 21 To July 22).