Zoisite n. : 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.

Example:
How can I polish a gemstone (ruby in Zoisite\) that is scratched across the surface?

Taxonomy
Zoisite, mineral, crystals, free encyclopedia, pale pink, mindat, Si2O7, purple, anyolite, tanzanite, striated, conchoidal, mineral dealer, m 2, principal axis, sorosilicate, epidote group, vitreous luster.

Defination from the web:
Zoisite was first known as saualpite, after its type locality. ... Sources of zoisite include Tanzania (tanzanite), Kenya (anyolite), Norway (thulite), Switzerland, Austria, India, Pakistan, and Washington in the ...