Outstanding specimen of two very rare platinum and palladium minerals: kotulskite (Pd telluride) and moncheite (Pt telluride) in a polished section that was analyzed by Bart Cannon using microprobe. Kotulskite is in the center of the circle (in the photo) and metallic golden moncheite is the rest of the sample. From: Stillwater Complex, Stillwater County, Montana, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Moncheite
Moncheite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pt(Te,Bi)₂.
It crystallizes in the hexagonal crystal system (space group P-3m1). It is a member of the Melonite structural group.
Key properties: specific gravity 9.88; Metallic luster.
IMA symbol Mon, IMA status: approved, named in 1963.
is typically found in small amounts in Pt–Pd-bearing massive Cu–Ni sulfide deposits.
It is found associated with Merenskyite, melonite, sobolevskite, michenerite, kotulskite, froodite, sperrylite, cooperite, laurite, braggite, insizwaite, gold, pyrrhotite, pentlandite.
The name is derived from the locality at Monche Tundra in Russia.