Melanothallite

IMA formula: Cu₂OCl₂

Crystallography: Orthorhombic. Fddd. a = 7.4691(15) Å, b = 9.5969(19) Å, c = 9.700(2) Å. Z = 8.

Specimen #49. Melanothallite and euchlorine. Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia. FOV 6.8 mm.