Outstanding reddish brown cryatals of then very rare mineral bosiite from Piedmont, Italy (Valletta Mine, Aisone, Cuneo Province, Piedmont, Italy). Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Bosiite
Bosiite is an IMA-recognized mineral species in the silicate class, with the chemical formula NaFe³⁺₃(Al₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O.
It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Tourmaline structural group.
Key properties: Mohs hardness 7; specific gravity 3.23; Dark brown streak; Vitreous luster; optically uniaxial.
IMA symbol Bos, IMA status: approved, named in 2014.
Found in a sulfide- and gold-bearing, sub-volcanic, hydrothermal quartz vein.
It is found associated with Quartz, pyrite, oxy-dravite, dravite, gold, calcite, dolomite, arsenopyrite, chalcopy rite, pyrrhotite, tetrahedrite, sphalerite, galena.
The mineral was named to honor Dr. Ferdinando Bosi (b. 1967), University of Rome La Sapienza, Italy.