What is Miargyrite?
Miargyrite is a specialist's ore mineral: its subdued black-grey colour hides silver-bearing chemistry and a dense sulfosalt structure. It becomes especially compelling in a documented association with stephanite, pyrargyrite or other silver minerals.
Mineralogy and crystal structure
Reference formula: AgSbS2. Miargyrite is a monoclinic silver antimony sulfide and a member of the tetrahedrite-tennantite-related sulfosalt world. Its dark metallic surfaces and high density are characteristic, but silver-bearing ore should remain labelled and enclosed. Miargyrite is classified with sulfosalts and has a monoclinic crystal system. Typical hardness is 2.5–3 on the Mohs scale and specific gravity is approximately 5.2–5.4.
Colour, lustre and habit
Typical colours include black, steel-grey, dark grey, red-brown. The usual prismatic, tabular, granular habit and metallic, sub-metallic lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Miargyrite forms in or is associated with low-temperature hydrothermal silver-antimony veins. Important documented localities include Mexico, Germany, Chile, Peru, Bolivia and the Czech Republic.
Dark metallic geometry in a silver vein
Miargyrite is a specialist's ore mineral: its subdued black-grey colour hides silver-bearing chemistry and a dense sulfosalt structure. It becomes especially compelling in a documented association with stephanite, pyrargyrite or other silver minerals.
Collecting and care
Keep enclosed from dust, avoid cutting and acids, and wash hands after handling.
