Ferdowsiite
Ferdowsiite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Ag₈(Sb₅As₃)S₁₆.
It crystallizes in the monoclinic crystal system (space group P2_1/n). It is a member of the Ferdowsiite structural group.
Key properties: Mohs hardness 2.5–3; specific gravity 5.3; Dark gray streak; Metallic luster.
IMA symbol Fdw, IMA status: approved, named in 2012.
Found in barite-quartz lenses in a metamorphosed strataform volcanogenic massive sulfide deposit.
It is found associated with Barite, ferroan tetrahedrite-tennantite, smithite, sterryite, bournonite, boulangerite, geocronite, galena, plumbian ferdowsiite, arsenquatrandorite.
The mineral was named to honor Ferdowsi Tousi (935-1020), the great Persian poet for his endeavors to preserve the national identity, language and heritage of his homeland.