Pyrargyrite Locality: Zacatecas, Mexico (Locality at mindat.org) Size: 5.3 x 3.7 x 3.3 cm. A very old Mexican specimen, from the 1800s, showing small crystals o — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Pyrargyrite
Also known as: Dark ruby silver.
Silver sulfantimonide — 'dark red silver ore' — a deep-ruby silver mineral and an important ore.
Intro adapted from Wikipedia (CC BY-SA).
Pyrargyrite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Ag₃SbS₃.
It crystallizes in the hexagonal crystal system (space group R3c).
Key properties: Mohs hardness 2.5; specific gravity 5.82; typically red or gray; Purplish red streak; Adamantine luster; optically uniaxial.
IMA symbol Pyg, grandfathered status — known before the IMA’s founding, named in 1831.
Formed in hydrothermal veins as a primary late-stage, low-temperature mineral; also formed by secondary processes.
It is found associated with Silver, acanthite, tetrahedrite, other silver sulfosalts, calcite, dolomite, quartz.
Its name comes from the Greek for fire and silver, in allusion to its composition and color.
Collections: Collector Favorites, Rare & Remarkable.