Zoisite is a mineral that includes several gem varieties. One form contains an opaque form of ruby (ruby in zoisite). The ruby in zoisite (or ruby zoisite) variety has also been called anyolite, derived from (anyoli)--the Masai tribal word for "green." Other named varieties of this gemstone include the opaque pink-to-red thulite and transparent purplish-blue tanzanite.
This stone was named after an Austrian naturalist and scientist named Sigmund Zois von Edelstein, who identified the stone as being a unique mineral specimen in his extensive collection.