Outstanding perfect dark yellow schoenfliesite crystals on a contrasting matrix. From: Zlaty Kopec, Bohemia, Czech Republic. Schoenfliesite is a very rare Mg-Sn hydroxide found in a few localities worldwide. — Photo: David Hospital · CC BY-SA 4.0
Schoenfliesite
Schoenfliesite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula MgSn(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 4; specific gravity 3.32.
IMA symbol Sfs, IMA status: approved, named in 1968.
A late-stage hydrothermal alteration product of hulsite in a boron-metasomatized limestone near the contact with a granite intrusive (Brooks Range, Alaska, USA).
It is found associated with Hulsite, goethite, maghemite (Brooks Range, Alaska, USA); cassiterite, berborite, calcite, fluorite, dolomite, magnetite, chondrodite.
The mineral was named to honor Arthur Moritz Schoenflies (1853–1928), Professor of Mathematics, University of Frankfurt-am-Main, Frankfurt, Germany, for his derivation of the 230 space groups.