Kermesite , Schafarzikite Locality: Pernek-Kriznica, Southwestern Slovakia, Slovak Republic (TYPE LOCALITY) Size: small cabinet, 6.2 x 3.5 x 2.2 cm Schafarzikite Xls on Kermesite Xls This is one of those weird minerals that, having never seen one for sale and finding the name unpronounceable, I admittedly just bought on trust that it is as rare as my supplier thought. I got it from Josef Vajdak of Peque Rare Minerals, in response to the usual "show me something neat and rare" question I ask him at shows. He says it is really good for what it is, and I will cede to his wisdom on the point. Josef is, after all, one of the better known Czech mineralogists and has a Czech mineral named after him, even. So, I figure he knows his minerals from the region! Comes with a copy of a scientific article on the find (in Czech) and an XRD analytical result set including photographs and data. 6.2 x 3.5 x 2.2 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Schafarzikite
Schafarzikite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe²⁺(Sb³⁺)₂O₄.
It crystallizes in the tetragonal crystal system (space group P4_2/mbc). It is a member of the Trippkeite structural group.
Key properties: Mohs hardness 3.5; specific gravity 4.3; Brown streak; Metallic luster; optically uniaxial.
IMA symbol Sfz, grandfathered status — known before the IMA’s founding, named in 1921.
Found in oxidized antimony-bearing hydrothermal mineral deposits.
It is found associated with Kermesite, valentinite, sénarmontite, stibnite, calcite (Pernek, Slovakia); apuanite, versiliaite, derbylite, bournonite, pyrite.
The mineral was named to honor Professor Ferenc Schafarzik (1854–1927), Hungarian mineralogist, of the Polytechnic, Budapest, Hungary.