Description
The mineral datolite is a boron-containing calcium silicate with the chemical formula CaB(SiO4)(OH). The mineral belongs to the nesosilicate family. Datolite, which is transparent to translucent, colorless, white, yellow, light green, or brown, has a vitreous luster, a white streak color, and is non-cleavable. Datolite has an average density of 2.9 and a hardness of 5.5. Its crystal system is monoclinic, and the mineral is not radioactive. The name of the mineral datolite is derived from the Greek word dateisthai, meaning "to separate." It is so named because datolite aggregates crumble easily. Datolite is a secondary mineral in mafic igneous rocks. The type locality is a diabase from the Connecticut River Valley in the United States.
