Miargyrite group of flat tabular flat smooth steel to dark grey colour (1.5 mm across) on a quartz matrix. The exact location is unknown, but should be assigned to California Rand Silver Mine, Red Mountain, San Bernardino County, California, USA - FOV 2x3 aprox — Photo: Maurizio Dini · CC BY 3.0
Miargyrite
Silver-antimony sulfide — 'ruby blende' — a dark-red to black mineral discovered at Freiberg in 1824.
Intro adapted from Wikipedia (CC BY-SA).
Miargyrite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula AgSbS₂.
It crystallizes in the monoclinic crystal system (space group C2).
Key properties: Mohs hardness 2.5; specific gravity 5.25; Cherry-red streak; Metallic adamantine luster; optically biaxial.
IMA symbol May, grandfathered status — known before the IMA’s founding, named in 1829.
Found in hydrothermal veins of low-temperature origin.
It is found associated with Baumstarkite, proustite, pyrargyrite, polybasite, silver, galena, sphalerite, pyrite, quartz, calcite, barite.
Its name comes from the Greek for less and silver, as it contains less silver than other red silver sulfosalt minerals. All rights reserved. No part of this publication may be reproduced.