Marthozite Locality: Musonoi Mine, Kolwezi , Western area, Katanga Copper Crescent, Katanga (Shaba) , Democratic Republic of Congo (Zaïre) ( Locality at mindat.org ) Size: small cabinet, 6.2 x 5.3 x 4.0 cm Marthozite Superb, unusually large marthozite crystals to 4.5 mm (twinned?) in a protective vug! — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Marthozite
An orthorhombic copper uranyl selenite named for Union Minière director Aimé Marthoz.
Intro adapted from Wikipedia (CC BY-SA).
Marthozite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu²⁺(UO₂)₃(Se⁴⁺O₃)₂O₂·8H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbn2_1).
Key properties: Mohs hardness 6; specific gravity 4.4; refractive index 1.79; optically biaxial.
IMA symbol Mhz, IMA status: approved, named in 1968.
A rare alteration product of selenian digenite in the oxidation zone of a uranium-bearing Cu-Co hydrothermal ore deposit.
It is found associated with Digenite, demesmaekerite, denningite, guilleminite.
The mineral was named to honor Airne Marthoz (1894-1962), former Director of the Union Miniere de Haut-Katanga, Congo.