Gerhardtite and Buttgenbachite - Tenke deposit, Congo (Zaire), Democratic Republic of the - 6.5 x 3 x 4 cm / main crystal: 2.8 cm.

Mineral: Gerhardtite and Buttgenbachite
Locality: Tenke deposit, Tenke-Fungurume area, Kolwezi District, Lualaba, Katanga Copper Crescent, Katanga (Shaba), Democratic Republic of the Congo (Zaire)
Dimensions: 6.5 x 3 x 4 cm / main crystal: 2.8 cm.

Description: Mass: 118 g MIM number:2174 Massive cuprite matrix in a cavity of which a very dark blue-green perfect gerhardtite crystal of parallelepiped shape has developed, formed of parallel layers and surrounded by small tufts of bright blue buttgenbachite. Part of the rear side of this crystal shows a natural cavity which is covered in places with microcrystals of a green mineral (brochantite or malachite). It is one of the largest and best formed crystals of this very rare nitrate known to date. Photographer: FMI / James Elliot