Fleetite
Fleetite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₂RhIrSb₂.
It crystallizes in the cubic crystal system (space group Fd-3m).
Key properties: Mohs hardness 10.83; specific gravity 10.83; Metallic luster.
IMA symbol Fle, IMA status: approved, named in 2020.
Found in a fluvial Au-PGE placer deposit. Formed originally by reaction of the associated alloy phases with a fluid phase enriched in Sb, As, and S circulating in a cooling ophiolitic rock.
It is found associated with Os-Ir-Ru alloys, i.e., the minerals osmium, ruthenium, and iridium; Pt-Fe alloys; platinum-group element (PGE) minerals, i.e., laurite, irarsite (Sb-rich).
The mineral was named to honor Dr. Michael Edward Fleet (1938-2017), Professor of mineralogy, Department of Earth Sciences, Western University, London, Ontario, Canada. Dr.