Okruschite
Okruschite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Ca₂Mn²⁺₅Be₄(AsO₄)₆(OH)₄·6H₂O.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Roscherite structural group.
Key properties: Mohs hardness 3.5; specific gravity 3.33; Vitreous luster; optically biaxial.
IMA symbol Okr, IMA status: approved, named in 2013.
Found in a hydrothermal vein cross-cutting rhyolite.
It is found associated with Braunite, Mn-bearing calcite, arseniosiderite.
The mineral was named to honor Professor Martin Okrusch (b. 1934), a German specialist in the mineralogy and petrology of magmatic and metamorphic rocks, ore petrology and ore deposits.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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