Ferrovorontsovite
Ferrovorontsovite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula (Fe₅Cu)TlAs₄S₁₂.
It crystallizes in the cubic crystal system (space group I-43m).
Key properties: Mohs hardness 3.5; specific gravity 4.744; Black streak; Metallic luster.
IMA symbol Fvor, IMA status: approved, named in 2017.
Found in mineralized limestone breccias (calcite-dolomite, up to 85% of volume) in the ores of the sulfide-carbonate type in a gold deposit of uncertain origin.
It is found associated with Cinnabar, realgar, stibnite, pyrite, dolomite, calcite.
The mineral was named to honor mining engineer Vladimir Vasilyevich Vorontsov (1842-later than 1908) for whom the city and mine are named where the new mineral was discovered. A prefix, ferro.