Berryite

Berryite is a mineral with the formula Pb₃(Ag,Cu)₅Bi₇S₁₆. It occurs as gray to blue-gray monoclinic prisms. It is opaque and has a metallic luster. It has a Mohs hardness of 3.5 and a specific gravity of 6.7.

It was first identified in 1965 using X-ray diffraction by mineralogist Leonard Gascoigne Berry (1914-1982). It is found in Park and San Juan counties in Colorado. It occurs in sulfide bearing quartz veins in Colorado and with siderite-rich cryolite in Ivigtut, Greenland.

References

* [http://webmineral.com/data/Berryite.shtml Webmineral data]
* [http://www.mindat.org/min-638.html Mindat with location data]
* [http://rruff.geo.arizona.edu/doclib/hom/berryite.pdf Mineral Data Publishing - PDF]