Prehnite

Description

Prehnite is an inosilicate of calcium and aluminium. Prehnite crystallizes in the orthorhombic crystal system and most often forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Very rarely will it form distinct, well-individualized crystals showing a square-like cross-section, including those found at the Jeffrey Mine in Asbestos, Quebec, Canada. Ca2Al(AlSi3O10)(OH)2