Miargyrite

Miargyrite is an uncommon silver sulfosalt. Though opaque and with a metallic luster, it may have slight translucent overtones of dark red, especially when containing arsenic in its structure which can replace some of the antimony. Arsenic is responsible for lightening up the color, and when the arsenic fully replaces the antimony, the mineral is no longer Miargyrite, but Smithite, a rare sulfosalt with a bright red color and transparency.

Miargyrite is named after the Greek word Meion - "less", and Argyros - "silver", since it contains a lesser percentage silver than other silver ores such as Pyrargyrite.

The type locality for Miargyrite is Bräunsdorf, Freiberg District, Erzgebirge, Saxony, Germany, where small but lustrous crystals have been found with Quartz. A classic European region for this mineral is Baia Sprie and Baia Mare (the Herja Mine), in Maramureș Co., Romania.

Perhaps the finest specimens of Miargyrite have come from the San Genaro Mine in Huancavelica Department, Peru, where it forms in relatively large examples for this species including thick crystal masses. In the U.S., crystallized examples as well as silvery masses come from the Kelly Mine, Randsburg, Kern Co., California.