Alite is a name for tricalcium silicate, Ca₃SiO₅, sometimes formulated as 3CaO·SiO₂ (C₃S in cement chemist notation, CCN). It is the major, and characteristic, mineral phase in Portland cement. The name was given by Törneborn in 1897 to a crystal identified in microscopic investigation of Portland cement. Alite is a name in common use in the cement industry, although it is not a recognised mineral name.