It also accentuates the wearer's nature, whether positive or negative. Moonstone's characteristic shimmer is known as schiller or adularescence , and is caused by the intergrowth of two different types of feldspar with different refractive indexes. Moonstones are usually cut in a smooth-domed cabochon shape to maximize this effect. Moonstones come in a variety of colors, ranging from colorless to gray, brown, yellow, green, or pink. Moonstone cats eye is also available.
Clarity ranges from transparent to translucent.
Sometimes moonstone will have an eye as well as a sheen. Another related feldspar variety is known as rainbow moonstone. In this variety of labradorite feldspar, the sheen is a variety of rainbow hues. The best moonstone has a blue sheen, perfect clarity, and a colorless body color. Fine moonstone is quite rare and becoming rarer.