Zoisite

Zoisite is a mineral group which was rarely used as a gemstone until tanzanite was discovered in 1967. Tanzanite is the deep blue variety which looks like a sapphire and is only mined in Tanzania. The zoisite group also contains pink thulite and varieties just called "white zoisite" and so forth, in green, yellow, white, gray, and brown.

Zois"ite (?), n. [After its discoverer, Von Zois, an Austrian mineralogist.] Min.

A grayish or whitish mineral occurring in orthorhombic, prismatic crystals, also in columnar masses. It is a silicate of alumina and lime, and is allied to epidote.

© Webster 1913.