Fedotovite

IMA formula: K₂Cu₃O(SO₄)₃

Crystallography: Monoclinic. C2/c. a = 19.037(6), b = 9.479(2), c = 14.231(5) Å, β = 111.04(3)°, Z = 8.

Specimen #41. Fedotovite. Yadovitaya fumarole, Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia. FOV 7.4 mm. This specimen has probably altered.