Golden-bronze metallic crystals of the very rare Ni-Bi sulphide mineral parkerite from Zinkwand, Obertalbach Valley, Liezen District, Styria, Austria. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Parkerite
Parkerite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Ni₃(Bi,Pb)₂S₂.
It crystallizes in the orthorhombic crystal system (space group Pmam).
Key properties: Mohs hardness 3; specific gravity 8.5; Black, shining streak; Metallic luster.
IMA symbol Prk, grandfathered status — known before the IMA’s founding, named in 1937.
Occurs as grains in other hydrothermal sulfide and arsenide minerals.
It is found associated with Galena, bismuth, bismuthinite, tetradymite, hessite, cubanite, maucherite, nickeline, sperrylite, gold, chalcopyrite, pyrrhotite, pentlandite, siegenite.
The name commemorates Professor Robert Lüling Parker (1893–1973), Swiss Federal Institute of Technology, Zurich, Switzerland.