labradorite

A usually brilliant blue or green variety of plagioclase feldspar that contains approximately equal proportions of sodium and calcium and occurs in silica-poor igneous rocks.

A lime-soda feldspar (see feldspar), one of the species intermediate between the lime feldspar, anorthite, and the soda feldspar, albite, but more closely allied to the former.

A kind of feldspar commonly showing a beautiful play of colors, and hence much used for ornamental purposes. The finest specimens come from Labrador. See feldspar.

A plagioclase feldspar mineral, calcium sodium aluminum silicate, often very coarsely crystalline, used as a decorative stone for carvings and building façades.