- Rheniite, Rhenium Sulfide
- Small Cabinet, 6.0 x 4.5 x 3.0 cm
- Kudriavy Volcano (Kudryavyi), Iturup Island, Kuril Islands, Sakhalinskaya Oblast, Far-Eastern Region, Russia
- Ex. Josef Vajdak
A very fascinating and recently described (2004) rare species formed under very hot conditions in volcanic fumerols at the type locality in Russia. Other than being alloyed with platinum group elements or a trace constituent in molybdenite, rheniite represents the only distinct rhenium-bearing species as a rhenium sulfide. This is a large, significant, and very rich specimen with abundant silvery bright wedge-shaped, 0.5 mm rheniite crystals. Exceptional. Fersman Mineralogical Museum and Josef Vajdak labels.