Images
Formula: BiSI
Iodide-Sulphide of bismuth
Crystal System: Orthorhombic
Specific gravity: 6.411 calculated
Streak: Brown
Colour: Dark red to black
Luminescence: Not fluorescent under UV
Environments
Localities
At the type locality, La Fossa crater, Vulcano Island, Lipari, Eolie Islands, Metropolitan City of Messina,
Sicily, Italy, demicheleite-(I) was found in the active medium-temperature (~250°C) intracrateric fumarole. It
is the first bismuth iodide-sulphide
so far (2010) discovered in a wholly natural environment, and corresponds to the already known synthetic compound. It occurs
as acicular to stout, translucent crystals up to 0.25 mm long in an altered pyroclastic
breccia, together with
demicheleite-(Br),
bismoclite, bismuthinite,
godovikovite, panichiite,
aiolosite, brontesite,
adranosite and other new phases under study in 2010
(MM 74.1.141-145).
Back to Minerals