:Single crystal of the extremely rare rhodium mineral miassite (Rh17S15) included in resin used for the analysis of the specimen. From: Miass River, Chelyabinsk Oblast, Russian Federation. Miassite is a rhodium suphide, and one of the very few rhodium minerals known. Rhodium is the rarest of the six platinum group elements (Pt, Pd, Os , Ir, Ru, Rh) in minerals. Analyzed specimen by Mikhail Murashko. — Photo: David Hospital · CC BY-SA 4.0
Miassite
A rhodium sulfide from the Urals' Miass River — remarkable as a naturally occurring superconductor.
Intro adapted from Wikipedia (CC BY-SA).
Miassite is an IMA-recognized mineral species in the sulfide class, with the chemical formula Rh₁₇S₁₅.
It crystallizes in the cubic crystal system (space group Pm3m).
Key properties: specific gravity 7.42; Metallic luster.
IMA symbol Mia, IMA status: approved, named in 1997.
Found in heavy-mineral concentrates from fluvial placer deposits derived from ophiolites or layered mafic intrusions.
It is found associated with Isoferroplatinum, cuprorhodsite, bowieite, vasilite, cooperite, keithconnite.
The name refers to the Miass River, Russia. Similar material formally named “prassoite”.