Cadmoselite is a rare
cadmium selenide
Cadmium selenide is an inorganic compound with the formula Cd Se. It is a black to red-black solid that is classified as a II-VI semiconductor of the n-type. It is a pigment, but applications are declining because of environmental concerns.
...
mineral with
chemical formula
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...
CdSe. Cadmoselite crystallizes in the
hexagonal
In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°.
Regular hexagon
A regular hexagon is d ...
system and occurs as black to pale grey opaque crystals and grains.
[http://rruff.geo.arizona.edu/doclib/hom/cadmoselite.pdf Handbook of Mineralogy][http://webmineral.com/data/Cadmoselite.shtml Webmineral data]
It was first described in 1957 for an occurrence in
Tuva
Tuva (; ) or Tyva (; ), officially the Republic of Tyva,; , is a Republics of Russia, republic of Russia. Tuva lies at the geographical center of Asia, in southern Siberia. The republic borders the Federal subjects of Russia, federal sub ...
. The mineral occurs as interstitial grains in
sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
formed under
reducing alkaline
In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...
diagenetic conditions.
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References
*Emsley, John. ''Nature's Building Blocks.'' Oxford, 2001.
Cadmium minerals
Selenide minerals
Hexagonal minerals
Minerals in space group 186
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