Moonstone's unearthly glow is caused by light scattering between microscopic layers of feldspar. Moonstone is the opalescent variety of orthoclase, with a blue or white sheen called adularescence. This is caused by the reflection of light from the internal structure, made up of alternating layers of albite and orthoclase feldspar. In Hindu mythology, moonstone was said to be made by solidified moonbeams. The best material is from Myanmar and Sri Lanka. Other areas include India, Madagascar, Brazil, USA, Mexico, Tanzania, and the European Alps.