a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
source: WordNet 3.0
a light brown the color of topaz
source: WordNet 3.0
A mineral occurring in rhombic prisms, generally yellowish and pellucid, also colorless, and of greenesh, bluish, or brownish shades. It sometimes occurs massive and opaque. It is a fluosilicate of alumina, and is used as a gem.
