Black acicular crystals of the rare Pb-Ag sulphide from a Colorado locality: Mike Mine, San Juan Co., Colorado, United States of America. Microprobed by Sid Williams. Ex Hartel collection. — Photo: David Hospital · CC BY-SA 4.0
Berryite
A dense, steel-gray lead-silver-bismuth sulfosalt forming monoclinic prisms.
Intro adapted from Wikipedia (CC BY-SA).
Berryite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₃Ag₂Pb₃Bi₇S₁₆.
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Meneghinite structural group.
Key properties: specific gravity 6.7.
IMA symbol Bry, IMA status: approved, named in 1965.
Found in quartz veins with other sulfides and sulfosalts, and in siderite-rich cryolite (Ivigtut, Greenland).
It is found associated with Emplectite, aikinite, cuprobismutite, cupropavonite (Colorado, USA); galena, chalcopyrite, sphalerite, quartz (Nordmark, Sweden); galena, cosalite, ourayite.
In honor of Professor Leonard Gascoigne Berry (1914–1982), Canadian mineralogist, Queen’s University, Kingston, Ontario, Canada, who obtained the first X-ray powder pattern of the mineral.