Highly reflective inclusions of the extremely rare mineral mummeite from the type locality in Alaska mine (Acapulco Adit, Alaska Mine, Poughkeepsie Gulch, San Juan County, Colorado, United States of America) in a polished specimen that was analyzed. Ex. Excalibur Mineral Company specimen. Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Mummeite
Mummeite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₀.₅₈Ag₃.₁₁Pb₁.₁₀Bi₆.₆₅S₁₃.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Pavonite structural group.
Key properties: Metallic luster.
IMA symbol Mum, IMA status: approved, named in 1986.
Found in hydrothermal base-metal sulfide vein deposits.
It is found associated with Chalcopyrite, sphalerite, pyrite, ourayite, schapbachite, heyrovskyite, quartz (Alaska mine, Colorado, USA).
The mineral was named to honor Dr. William Gustav Mumme (1936–), Australian mineralogist, C.S.I.R.O., Melbourne, Australia, who first studied the mineral, for his work with sulfosalts.