Tin does not occur naturally by itself, and must be extracted from a base compound, usually cassiterite, stannite, cylindrite, franckeite, canfieldite, and teallite
. Tin content of Buriganga river sediment ranges from 2.9 to 6.4 [micro]g [g.sup.-1].
Such is the case of teallite
, a rare sulfide of tin and lead that is one of the main ore minerals at the Carguaicollo mine in Bolivia.
It appears also as pseudomorphs after pyrrhotite and, rarely, after teallite
[Contributions to the Knowledge of Bolivian Mineralogy, IV, Teallite
The sulfides and Sulfosalts are very well represented, most notably arsenopyrite, bismuthinite, bournonite, cylindrite, franckeite, pyrargyrite, pyrite, stannite, stibnite, teallite
, and wurtzite Among the oxides, cassiterite and quartz are most important and siderite is the most important carbonate.
General appearance: It has an overall similarity to teallite
. As layers (up to 1 cm thick) composed of tabular prismatic crystals elongated along  and as individual euhedral almost needle-like crystals.
comm.) reports the identification of lath-like crystals of teallite
to 5 mm in polished sections.