Outstanding prismatic crystal of the very rare Ni Cu Bi sulphide mineral muckeite from the type and only known locality worldwide, the Grune Au mine (=Gruneau mine), Germany, and associated to hairy golden millerite. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Mückeite
Mückeite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula CuNiBiS₃.
It crystallizes in the orthorhombic crystal system (space group P2_12_12_1). It is a member of the Lapieite structural group.
Key properties: Mohs hardness 3.5; specific gravity 5.88; Grayish black streak; Metallic luster; optically biaxial.
IMA symbol Müc, IMA status: approved, named in 1988.
Found in dump material at a polymetallic hydrothermal deposit, topotactically relacing lapieite.
It is found associated with Lapieite, millerite, bismuthinite, sphalerite, aikinite, polydymite.
The mineral was named to honor Dr. Arno Mücke (1937–), German mineralogist, Mineralogical-Petrological Institute, Göttingen University, Göttingen, Germany.