Strunz classification 4.JJ.05 Space group Pbn21 | Crystal system Orthorhombic | |
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Category Oxide mineral (uranyl selenite) Formula
(repeating unit) Cu(UO2)3(SeO3)3(OH)2·7H2O Crystal class Pyramidal (mm2)
(same H-M symbol) | ||
Marthozite is an orthorhombic mineral that has a general formula of Cu(UO2)3(SeO3)3(OH)2·7H2O. It was named after French mineralogist Aime Marthoz, former Director-general of the Union Miniere du Haut Katanga.
It is usually found in cavities in selenian digenite. It is specifically found in the zones of oxidation of the Musonoi deposit in Katanga, Africa.
Marthozite is orthorhombic, meaning that it has three axes of unequal lengths all orthogonal to each other. Since it is orthorhombic, marthozite is biaxial, meaning that it has three different indices of refraction. Marthozite is anisotropic, which means that it breaks light into one fast ray and one slow ray. Marthozite shows pleochroism from yellowish brown to greenish yellow.
References
Marthozite Wikipedia(Text) CC BY-SA