This gem is mainly produced in Sri Lanka, Myanmar, India, Brazil, Mexico and Alps in Europe, among which Sri Lanka is the most precious. Moonstone is usually colorless to white, but also light yellow, orange to light brown, blue gray or green, transparent or translucent, with special moonlight effect, hence the name. This gem has a slight blue or gray luster. When cleavage plane exists, it may be accompanied by interference or diffraction. The comprehensive effect of feldspar on light makes the surface of feldspar produce a blue floating light. If the layer is thick, it will produce grayish white, and the floating light effect will be worse. Sri Lankan Bai Yueguang stone is a precious gem, and its quality and value depend on its origin, color, transparency, luster and many other factors.