Ardaite is a very rare sulfosalt mineral with chemical formula Pb19Sb13S35Cl7 in the monoclinic crystal system, named after the Arda River, which passes through the type locality. == Discovery and occurrence== It was discovered in 1978 and approved by the International Mineralogical Association in 1980. It was the second well-defined natural chlorosulfosalt, after . thumb|left|Paragenesis of ardaite and [[galena, Madjarovo ore deposit, Bulgaria, at the National Museum of Natural History, Bulgaria]]
Ardaite is a very rare sulfosalt mineral with chemical formula Pb19Sb13S35Cl7 in the monoclinic crystal system, named after the Arda River, which passes through the type locality. == Discovery and occurrence== It was discovered in 1978 and approved by the International Mineralogical Association in 1980. It was the second well-defined natural chlorosulfosalt, after . thumb|left|Paragenesis of ardaite and [[galena, Madjarovo ore deposit, Bulgaria, at the National Museum of Natural History, Bulgaria]]
Greenish gray or bluish green in color, its luster is metallic. Ardaite occurs as 50 μm fine-grained aggregates of acicular crystals associated with galena, pyrostilpnite, anglesite, nadorite, and chlorine-bearing robinsonite and semseyite, in the Madjarovo polymetallic ore deposit in Bulgaria. Ardaite has a hardness of 2.5 to 3 on Mohs scale and a density of approximately 6.44.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).