Stannite

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Stannite
General
CategorySulfide mineral
Formula
(repeating unit)
Cu2FeSnS4
IMA symbolStn[1]
Strunz classification2.CB.15a
Crystal systemTetragonal
Crystal classScalenohedral (42m)
H-M symbol: (4 2m)
Space groupI42m
Unit cella = 5.4432, c = 10.7299 [Å]; Z = 2
Identification
ColorSteel-gray to iron-black, may tarnish blue
Crystal habitRarely as pseudo-octahedral crystals also massive, granular, and disseminated
TwinningPenetration twins on {102}
CleavageIndistinct on {110} and {001}
FractureUneven
Mohs scale hardness4
LusterMetallic
StreakBlack
DiaphaneityOpaque
Specific gravity4.3 – 4.5
References[2][3][4]

Stannite is a mineral, a sulfide of copper, iron, and tin, in the category of thiostannates.

Background[edit]

The chemical formula is Cu2FeSnS4. Zinc commonly occurs with the iron and trace germanium may be present.[4] Stannite is used as an ore of tin, consisting of approximately 28% tin, 13% iron, 30% copper, 30% sulfur by mass. It is found in tin-bearing, hydrothermal vein deposits occurring with chalcopyrite, sphalerite, tetrahedrite, arsenopyrite, pyrite, cassiterite, and wolframite.[2]

It is also known as bell metal ore as tin is an important constituent of bell-metal. It is thought the exploitation of tin deposits in Cornwall led to an expansion in bell founding.

The name comes from the Latin for tin: stannum. It was first described in 1797 for an occurrence in Wheal Rock, St. Agnes, Cornwall, England.[4]

See also[edit]

References[edit]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b "Stannite" (PDF). Handbook of Mineralogy.
  3. ^ "Stannite". Webmineral data.
  4. ^ a b c "Stannite". Mindat.org.