Very well formed pale yellow long microcrystals of the extremely rare relatively new mineral hephaitosite (IMA 2006-043) in an aesthetic composition. Hephaistosite is a thallium-lead chloride (TlPb2Cl5) only found at La Fossa Crater worldwide (Vulcano Island, Aeolian Islands, Sicily, Italy). — Photo: David Hospital · CC BY-SA 4.0
Hephaistosite
Hephaistosite is an IMA-recognized mineral species in the halide class, with the chemical formula TlPb₂Cl₅.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: specific gravity 5.932.
IMA symbol Hep, IMA status: approved, named in 2006.
On fragments of altered pyroclastic breccia in a high temperature (400° C) fumarole, most likely formed as a sublimate.
It is found associated with Bismuthinite, cotunnite, challacolloite, pseudocotunnite.
The name refers to Hephaistos, the Greek god of fire, whose workshops were believed to be located at Vulcano.