Acanthite

Acanthite is a naturally occurring mineral form of silver sulfide, meaning it is composed of silver and sulfur atoms bonded together. It typically forms in dark, metallic-looking crystals and is an important ore of silver, often extracted for its metal content. Found in hydrothermal veins and associated with other sulfide minerals, acanthite is dark gray to black and has a shiny, metallic luster. It is relatively stable at low temperatures but can change to other silver minerals under different conditions. Its distinctive appearance and silver content make it valuable in jewelry, collector specimens, and metal extraction.