Stromeyerite and baryte on chert from Zmeinogorsky District, Altai mountains, Russia — Photo: Kritzolina · CC BY-SA 4.0
Stromeyerite
Copper-silver sulfide — 'copper-silver glance' — an opaque blue-gray mineral of silver veins.
Intro adapted from Wikipedia (CC BY-SA).
Stromeyerite is an IMA-recognized mineral species in the sulfide class, with the chemical formula CuAgS.
It crystallizes in the orthorhombic crystal system (space group Cmc2_1).
Key properties: Mohs hardness 2.5–3; specific gravity 6.2–6.3; Steel-gray streak; Metallic luster.
IMA symbol Smy, grandfathered status — known before the IMA’s founding, named in 1832.
Found in hydrothermal veins, formed most commonly by secondary processes, although it also forms as a primary mineral.
It is found associated with Freibergite, bornite, chalcopyrite, galena, other sulfides.
In honor of Professor Friedrich Stromeyer (1776–1835), chemist and mineralogist, University of Göttingen, Göttingen, Germany, who first analyzed the mineral.