stannite

{{infobox mineral | name = Stannite | category = Sulfide mineral | boxwidth = | boxbgcolor = | image = Stannite-Chalcopyrite-Quartz-168837.jpg | imagesize = 260px | alt = | caption = | formula = Cu2FeSnS4 | IMAsymbol = Stn | molweight = | strunz = 2.CB.15a | dana = | system = Tetragonal | class = Scalenohedral (2m) H-M symbol: ( 2m) | symmetry = I2m | unit cell = a = 5.4432, c = 10.7299 [Å]; Z = 2 | color = Steel-gray to iron-black, may tarnish blue | colour = | habit = Rarely as pseudo-octahedral crystals also massive, granular, and disseminated | twinning = Penetration twins on {102} | cleavage = Indistinct on {110} and {001} | fracture = Uneven | tenacity = | mohs = 4 | luster = Metallic | streak = Black | diaphaneity = Opaque | gravity = 4.3 – 4.5 | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence= | absorption = | melt = | fusibility = | diagnostic = | solubility = | other = | alteration = | references = }} Stannite is a mineral, a sulfide of copper, iron, and tin, in the category of thiostannates.

==Background== The chemical formula is Cu2FeSnS4. Zinc commonly occurs with the iron and trace germanium may be present. 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.