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 Pb
16Sb
18S
43 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, ...
, USA
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
.[
]
See also
*
References
{{wiktionary
Sulfosalt minerals
Lead minerals
Monoclinic minerals
Antimony minerals