Miargyrite

Description

Miargyrite has a hardness of 2½ and a specific gravity of 5.25. According to Mindat, it was “named from Greek ‘meion’ (less) and ‘argyros’ (silver), for it contains less silver than pyrargyrite which it was often mistaken for.” Also from Mindat, Miargyrite is often found as “black blocky, often striated crystals with dark red internal reflections to a cm. The crystals are difficult to orient and often form balls to a few cm.”

Found in 16 localities within Colorado, and around 337 total localities worldwide on every Continent but Antarctica (so far), usually near low temperature hydrothermal deposits associated most often with Pyrargyrite, Quartz, Calcite, Barite, and additional minerals composed of Antimony, Iron, Zinc, and Silver Sulfides.

WebMineral shows an assayed specimen contained roughly 41% Antimony, 37% Silver, and 22% Sulfur. Even though it may not have as much Silver as a Silver specimen, or as much Antimony as a Stibnite specimen, or as much Sulfur as a Sulfur specimen, it’s still an awesome rock for element collectors to represent any of those elements!

However, this may be even more valued by Colorado rock collectors, as this is a pretty special specimen from a pretty famous mine!

If you just so happen to be out hiking near any low temperature hydrothermal deposits with Quartz and black crystals, be on the look out for this cool mineral, and you might just find your next Silver mine!