Used for the production of silver
Argentite was primarily treated as a mineral belonging to the Galena group, cubic silver sulfide, occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre. All these forms are structurally not argentite, but its monoclinic polymorph, acanthite. The cubic cleavage, which is so prominent a feature in galena, here present only in traces. The mineral is perfectly sectile and has a shining streak; hardness 2.5, specific gravity 7.2-7.4. It occurs in mineral veins, and when found in large masses, it forms an important ore of silver.