Sardignaite
Sardignaite is an IMA-recognized mineral species in the molybdate class, with the chemical formula BiMo₂O₇(OH)·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/m).
Key properties: Mohs hardness 3; specific gravity 4.82; White streak; Adamantine luster.
IMA symbol Sdi, IMA status: approved, named in 2008.
A secondary mineral formed in the oxidation zone of a molybdenite-bismuthinite deposit in quartz veins within a granite.
It is found associated with Bismuthinite, bismoclite, molybdenite, ferrimolybdite, koechlinite, wulfenite, gelosaite.
The name refers to Sardigna (in Italian “Sardegna”, in English “Sardinia”), the region in which the mineral was found, as spelt in the local language, which is an independent Romance language.