Krokoit, Vauquelinit, Phönikochroit, Quarz, Muskovit Fundort: Grube Beresowsk bei Jekaterinburg, Ural, ca. 1846 — Photo: Kaethe17 · CC BY-SA 4.0
Vauquelinite
A rare copper-lead chromate-phosphate forming a series with fornacite.
Intro adapted from Wikipedia (CC BY-SA).
Vauquelinite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CuPb₂(CrO₄)(PO₄)(OH).
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 2.5–3; specific gravity 6.16; typically green or brown or black; Greenish to brownish streak; Adamantine to resinous luster; refractive index 2.183; optically biaxial.
IMA symbol Vql, grandfathered status — known before the IMA’s founding, named in 1818.
A rare mineral found in the oxidized zones of some hydrothermal base-metal deposits.
It is found associated with Crocoite, pyromorphite, mimetite, cerussite, beudantite, duftite (Beresovsk, Russia).
The mineral was named to honor Professor Louis Nicolas Vauquelin (1763–1829), French chemist, University of Paris, Paris, France, who discovered chromium.
Collections: Collector Favorites, Rare & Remarkable.