Moonstone exists in numerous colors, including blue, grey, white, pink, peach, green and brown, as well as colorless. Deposits of moonstone occur in Armenia (mainly from Lake Sevan), Australia, the Austrian Alps, Mexico, Madagascar, Myanmar, Norway, Poland, India, Sri Lanka and the United States.
Moonstone is a sodium potassium aluminium silicate ((Na,K)AlSi3O8) of the feldspar group that displays a pearly and opalescent schiller. Its name is derived from a visual effect, sheen or schiller (play of color), caused by light diffraction within a micro-structure consisting of regular exsolution layers (lamellae) of different alkali feldspars (orthoclase and sodium-rich plagioclase).
Moonstone has been used in jewelry for millennia, including ancient civilizations. The Romans admired moonstone, as they believed it was born from solidified rays of the Moon. Both the Romans and Greeks associated moonstone with their lunar deities. In more recent history, moonstone became popular during the Art Nouveau period; French goldsmith René Lalique and many others created a large quantity of jewelry using this stone.