vesuvianite n 1: a green or yellow or brown mineral consisting of a hydrated silicate; it occurs as crystals in limestone and is used a gemstone [syn: {vesuvianite}, {vesuvian}, {idocrase}]
Vesuvianite \Ve*su"vi*an*ite\, n. (Min.) A mineral occurring in tetragonal crystals, and also massive, of a brown to green color, rarely sulphur yellow and blue. It is a silicate of alumina and lime with some iron magnesia, and is common at Vesuvius. Also called {idocrase}. [1913 Webster]