Ardaite is a very rare

sulfosalt mineral Sulfosalt minerals are sulfide minerals with the general formula , where *A represents a metal such as copper, lead, silver, iron, and rarely mercury, zinc, vanadium *B usually represents semi-metal such as arsenic, antimony, bismuth, and ra ...

with chemical formula Pb₁₉Sb₁₃S₃₅Cl₇ in the

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic ...

crystal system In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their poi ...

, named after the Arda River, which passes through the type locality. It was discovered in 1978 and approved by the

International Mineralogical Association Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. Th ...

in 1980. It was the second well-defined natural chlorosulfosalt, after dadsonite. 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 Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cry ...

, pyrostilpnite,

anglesite Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and ...

nadorite Nadorite is a mineral with the chemical formula PbSbO2Cl. It crystallizes in the orthorhombic crystal system and is brown, brownish-yellow or yellow in color, with a white or yellowish-white streak. Nadorite is named after Djebel Nador in Alger ...

, and

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...

-bearing robinsonite and

semseyite Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead antimony sulfides. It crystallizes in the monoclinic system with the chemical composition Pb9Sb8S21. The mineral forms dark gray to black aggregates. Etymology ...

, in the Madjarovo polymetallic ore deposit in Bulgaria. Ardaite has a hardness of 2.5 to 3 on

Mohs scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the ...

and a density of approximately 6.44. The

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

is the Madjarovo polymetallic ore deposit in the

Rhodope Mountains The Rhodopes (; bg, Родопи, ; el, Ροδόπη, ''Rodopi''; tr, Rodoplar) are a mountain range in Southeastern Europe, and the largest by area in Bulgaria, with over 83% of its area in the southern part of the country and the remainder i ...

. Later its occurrence was proved in the Gruvåsen deposit, near

Filipstad Filipstad is a locality and the seat of Filipstad Municipality, Värmland County, Sweden, with 10,644 inhabitants in 2019. Filipstad was granted city privileges in 1611 by Charles IX of Sweden, who named it after his son Duke Carl Philip (1601&n ...

Bergslagen Bergslagen is a historical, cultural, and linguistic region located north of Lake Mälaren in northern Svealand, Sweden, traditionally known as a mining district. In Bergslagen, the mining and metallurgic industries have been important since ...

, Sweden.

References

External links

* {{wiktionary Sulfosalt minerals Lead minerals Monoclinic minerals Antimony minerals