Yellow Wickmanite crystal Picture width: 3 mm Locality: Pitkyaranta mining district, Pitkyarantsky District, Republic of Karelia, Russia ( Locality on mindat.org ) — Photo: Leon Hupperichs · CC BY-SA 3.0
Wickmanite
Wickmanite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mn²⁺Sn⁴⁺(OH)₆.
It crystallizes in the cubic crystal system (space group Pn3). It is a member of the Perovskite structural group.
Key properties: Mohs hardness 3.5; specific gravity 3.89; White streak; Resinous luster.
IMA symbol Wm, IMA status: approved, named in 1965.
A rare late-stage, low-temperature mineral in magnetite ore and jacobsite- richterite-manganoan biotite skarn in a metamorphosed Fe–Mn orebody (Långban, Sweden); in a nepheline syenite pegmatite (Tvedalen, Norway).
It is found associated with Bementite, allactite, calcite, barite, magnetite (Långban, Sweden); burtite, stokesite, datolite, pectolite, apophyllite (El Hamman, Morocco); stokesite.
The mineral was named to honor Professor Franz-Erik Wickman (1915–), Swedish-American mineralogist, for his contributions to Långban mineralogy.