#silver sulfide

• Acanthite — A mineral belonging to the sulfide class, representing the low-temperature monoclinic crystalline form (stable below 173°C) of silver sulfide (Ag2S). This precious and heavy mineral is frequently found in hydrothermal veins or secondary enrichment zones of silver ore deposits, showcasing a lead-gray to black color with a dull metallic luster. It is dimorphous with argentite, the cubic mineral that pseudomorphically converts into acanthite upon natural cooling.
• Argentite — A mineral from the sulfide class, composed of silver sulfide with the chemical formula Ag2S, structurally stable only at temperatures above 173°C. At ambient temperatures, it transforms through pseudomorphosis into acanthite (its stable monoclinic modification), while retaining its initial outer cubic form. Industrially, it is an extremely important silver ore, featuring a dark grey to black color, a bright metallic luster, and high density.
• Argyrite — An archaic or literary mineralogical designation historically used as a synonym for argentite or silver sulfide (Ag2S), or for other silver-rich ores. In a structural and historical sense, the term represents a transitional form borrowed from Western European and Hellenic scientific terminology (based on the root argyros - silver), encountered in old geology treatises and mining catalogs before the standardization of modern international nomenclature.