Grey metallic crystals of the very rare mineral kirkiite, a Pb-Bi sulphosalt from the type locality in Kirki (Agios Philippos Mine, Kirki, Evros, East Macedonia and Thrace, Greece), the same place which produces nice wurtzite crystals. Kirkiite is found in only three localities worldwide and is usually massive, however this sample has a few crystal aggregates. — Photo: David Hospital · CC BY-SA 4.0
Kirkiite
Kirkiite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₁₀Bi₃As₃S₁₉.
It crystallizes in the monoclinic crystal system (space group P2_1/m).
Key properties: specific gravity 6.8.
IMA symbol Krk, IMA status: approved, named in 1984.
Found in a hydrothermal Pb-Zn deposit (Kirki, Greece); in a volcanic fumarole, formed at about 470 flC (Vulcano, Italy).
It is found associated with Cosalite, bismuthinite, bismuthian jordanite, seligmannite, levyclaudite, sphalerite, pyrite, galena (Kirki, Greece); vurroite, galena, bismuthinite.
The name refers to Kirki, Greece.