Silvery black crystal aggregates of the extremely rare Pb-Bi telluride mineral aleksite from one of the few known localities worldwide on a contrasting matrix. From: Keystone Canyon, Nye County, Nevada, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Aleksite
A rare lead-bismuth-tellurium sulfosalt.
Intro adapted from Wikipedia (CC BY-SA).
Aleksite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula PbBi₂Te₂S₂.
It crystallizes in the hexagonal crystal system (space group P-3m1). It is a member of the Tetradymite structural group.
Key properties: specific gravity 7.57.
IMA symbol Alk, IMA status: approved, named in 1977.
Of hydrothermal origin in sulfide-quartz veins (Alekseev mine, Russia).
It is found associated with Galena, gold, altaite, tetradymite, tsumoite, rucklidgeite, quartz (Alekseev mine, Russia).
The name refers to the Alekseev mine, Russia.