Titanium

Titanium (Ti = 50) is a rare metal, which was discovered towards the close of the last century in the mineral menaccanite. The pure metal is only obtained with much difficulty, and, if heated in air or oxygen, burns with great brilliancy. Its oxide (TiO₂) is the chief source of the metal and its compound, and is remarkable, as it occurs in three distinct crystalline forms of varying specific gravity and other physical characters. These forms are known as anatase (q.v.), rutile (q.v.), and brookite (q.v.). With alkalies it forms unstable salts, the titanates, but neither these nor the salts of titanium itself are of any commercial importance.