Metallic microinclusions of the extremely rare Ag mineral larosite from the type locality in Foster mine (Foster Mine, Coleman Township, Cobalt, Timiskaming District, Ontario, Canada) in a matrix of chalcosine, in an analyzed specimen by SEM/EDS by the former owner of the specimen (the Vandenbroucke Museum) but the analysis is no longer available. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Larosite
Larosite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula (Cu,Ag)₂₁PbBiS₁₃.
It crystallizes in the orthorhombic crystal system.
Key properties: specific gravity 6.19; Metallic luster.
IMA symbol Lar, IMA status: approved, named in 1971.
Found in the central portion of a layered hydrothermal vein.
It is found associated with Chalcocite, stromeyerite, arsenopyrite, galena, tetrahedrite, polybasite.
The mineral was named to honor Frederick Alfred LaRose, Canadian blacksmith, one of the discoverers of silver ore at Cobalt.