datolite

noun

1. a mineral, calcium and boron silicate, CaB(SiO4)(OH), usually occurring in rock cavities in the form of colorless, prismatic crystals.

noun

1. a colourless mineral consisting of a hydrated silicate of calcium and boron in monoclinic crystalline form, occurring in cavities in igneous rocks. Formula: CaBSiO 4 (OH)