Playfairite is a 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 rarely ...

with chemical formula Pb₁₆Sb₁₈S₄₃ 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 s ...

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 poin ...

, named after the Scottish scientist and mathematician

John Playfair John Playfair FRSE, FRS (10 March 1748 – 20 July 1819) was a Church of Scotland minister, remembered as a scientist and mathematician, and a professor of natural philosophy at the University of Edinburgh. He is best known for his book ''Illu ...

. It was discovered in 1966 by the Canadian mineralogist John Leslie Jambor.Lynne Jambor and John Dutrizac (2008), ''Memorial of John L. Jambor (1936-2008)'', American Mineralogist, vol. 93, pp. 710-712
/ref> Lead gray to black in color, its luster is metallic. Playfairite shows strong reflection

pleochroism Pleochroism (from Greek πλέων, ''pléōn'', "more" and χρῶμα, ''khrôma'', "color") is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light. Backgrou ...

from white to brownish gray. Playfairite has a hardness of 3.5 to 4 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 th ...

and a

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...

of approximately 5.72. The type locality is Taylor Pit (Concession XIV; Lot 13), Huntingdon Township, Hastings County in

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. Small deposits have also been found in Les Cougnasses Mine,

Orpierre Orpierre (; oc, Aurpèira) is a Communes of France, commune in the Hautes-Alpes Departments of France, department in southeastern France. The village has multiple venues for sport climbing nearby; one is directly to the north of the village. Po ...

in the Haut-Alpes in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

, Khaidarkan Sb-Hg deposit (Chaidarkan),

Fergana Valley The Fergana Valley (; ; ) in Central Asia lies mainly in eastern Uzbekistan, but also extends into southern Kyrgyzstan and northern Tajikistan. Divided into three republics of the former Soviet Union, the valley is ethnically diverse and in the ...

, Alai Range,

Osh Oblast Osh Region ( ky, Ош облусу, translit=Osh oblusu; russian: Ошская область, Oshskaya oblast) is a region (''oblast'') of Kyrgyzstan. Its capital is Osh, which is not part of the region. It is bounded by (clockwise) Jalal-Abad R ...

Kyrgyzstan Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...

and Reese River District, Lander County,

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

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References

{{wiktionary Sulfosalt minerals Lead minerals Monoclinic minerals Antimony minerals

See also

References