Ardaite

Ardaite is a very rare sulfosalt mineral with chemical formula Pb₁₉Sb₁₃S₃₅Cl₇ in the monoclinic crystal system,^[2][3] named after the Arda River, which passes through the type locality.^[4]

Ardaite
Ardaite associated with galena, Madjarovo polymetallic ore deposit, National Museum of Natural History, Bulgaria
General
Category	Sulfosalt minerals, Lead minerals
Formula	Pb19Sb13S35Cl7
IMA symbol	Ada[1]
Strunz classification	2.LB.30 (10 ed) 2/E.19-20 (8 ed)
Dana classification	02.15.01.01
Crystal system	Monoclinic Unknown space group
Identification
Color	Greenish gray or bluish green
Mohs scale hardness	2.5-3
Luster	Metallic
Density	6.44
Pleochroism	Weak
References	Breskovska, V. V.; Mozgova, N. N.; Bortnikov, N. S.; Gorshkov, A. I.; Tzepin, A. I. (1982), "Ardaite, a new lead-antimony chlorsulphosalt" (PDF), Mineral. Mag., 46 (340): 357–361, Bibcode:1982MinM...46..357B, doi:10.1180/minmag.1982.046.340.10, S2CID 128756669

Discovery and occurrence

It was discovered in 1978 and approved by the International Mineralogical Association in 1980.^[5][6][7] It was the second well-defined natural chlorosulfosalt, after dadsonite (Wikidata).^[8]

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.^[2]

The type locality is the Madjarovo polymetallic ore deposit in the Rhodope Mountains.^[9][10] Later its occurrence was proved in the Gruvåsen deposit, near Filipstad, Bergslagen, Sweden.^[6]

See also

List of minerals recognized by the International Mineralogical Association