Danburite

Mineral formula: CaB₂Si₂O₈

Crystal system: orthorhombic

Crystal habit: prismatic crystals, disseminated masses

Cleavage: poor/indistinct on {001}

Fracture: irregular/uneven, subconchoidal

Color: pale yellow, yellowish brown, colorless

Luster: vitreous, greasy

Diaphaneity: Transparent to translucent

Moh’s scale hardness: 7 – 7 ½

Streak: white

Specific gravity:  2.93 – 3.02

Type locality: Danbury, Connecticut, USA

Geological occurrence: Granite and metamorphosed carbonates, evaporites.

Named for: the type locality – Danbury, Connecticut.