Wilhelmramsayite
Wilhelmramsayite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu₃FeS₃·2H₂O.
It crystallizes in the orthorhombic crystal system (space group Pmmm).
Key properties: Mohs hardness 2.5; specific gravity 2.75; Black streak; Metallic luster.
IMA symbol Wrm, IMA status: approved, named in 2004.
A late hydrothermal phase in the core of an ultra-agpaitic pegmatite dominated by aegirine, microcline, sodalite, natrolite, pectolite, villaumite, ± natrite, thermonatrite, lomonosovite.
It is found associated with Villaumite, pectolite, rasvumite, lamprophyllite, lomonosovite, chkalovite, sphalerite, vitusite-(Ce).
The mineral was named to honor Finnish geologist Wilhelm Ramsay (1865-1928), who did the first detailed study of the Khibiny-Lovozero alkaline complexes.