Feldspar

Feldspar is a group of minerals that make up one of the most abundant rock-forming minerals on Earth’s crust.

Common feldspar group minerals include albite, anorthite, oligoclase, orthoclase, and microcline. Various combinations of these can form as Labradorite, Rainbow Moonstone, Moonstone, and Amazonite.

They are often used as gemstones, as many have interesting optical properties such as chatoyance and play of colour.