Ardaite

Ardaite is a very rare sulfosalt mineral with chemical formula Pb₁₉Sb₁₃S₃₅Cl₇ in the monoclinic crystal system,[1][2] named after the Arda river, which passes through the type locality.[3] It was discovered in 1978 and approved by the International Mineralogical Association in 1980.[4][5][6] It was the second well-defined natural chlorosulfosalt, after dadsonite.[7]

Ardaite
Ardaite associated with galenite, Madjarovo polymetallic ore deposit, National Natural History Museum, Sofia, Bulgaria
General
Category	Sulfosalt minerals, Lead minerals
Formula (repeating unit)	Pb19Sb13S35Cl7
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: 357–361

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 Cl-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.[1]

The type locality is the Madjarovo polymetallic ore deposit in the Rhodope mountains.[8][9] Later its occurrence was proved in the Gruvåsen deposit, near Filipstad, Bergslagen, Sweden.[5]

References

1. Mindat information page for Ardaite
2. Webmineral information page for Ardaite
3. Handbook of Mineralogy information page for Ardaite
4. 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: 357–361
5. Burke, E.A.J.; Kieft, C.; Zakrzewski, M.A. (1981), "The Second Occurrence of Ardaite" (PDF), Canadian Mineralogist, 19: 419–422, retrieved 3 May 2018
6. Dunn, Pete; Fleischer, Michael (1983), "New Mineral Names" (PDF), American Mineralogist, 68: 642–45
7. Zelenski, Michael; Zunic, Tonci Balic; Bindi, Luca; Caravelli, Anna; Makovicky, Emil; Pinto, Daniela; Vurro, Filippo (2006), "First Occurrence of Iodine in Natural Sulfosalts: The Case of Mutnovscite" (PDF), American Mineralogist, 91: 21–28
8. See the Collection of Minerals at the National Natural History Museum, Sofia, Bulgaria
9. See the Madjarovo deposit at Mindat.com

Paragenesis of ardaite & galena, Madjarovo ore deposit, Bulgaria, National Natural History Museum, Sofia, Bulgaria

See also

List of minerals approved by IMA