Mineral description : Cassiterite

Cassiterite from Varuträsk.
In cleavelandite and quartz. Cassiterite from Varuträsk.
3 cm piece with biotite.

Mineral class Oxides : Rutil-cassiterite group.

Chemical formula SnO₂

Crystal system Tetragonal.

Habitus Often as short prismatic crystals. Also as small grains or banded fibric masses.

Cleavage Poor, fracture subconchoidal to uneven.

Hardness 6-7

Density 6.8-7.1

Color Black, but also yellowish and colorless. Translucent to opaque.

Streak White to weakly brownish.

Luster Adamantine, greasy on fractures.

Description

Occurance In pegmatites, high temperature hydrothermal veins and some metamorphic rocks.

Associates

Notes Cassiterite is insoluble in acids and infusible.

Locations A rare mineral in Sweden.

Varuträsk, Västerbotten. Common as poorly developed crystals, streak color reddish brown.
Utö, Stockholm. As small grains.
Finnbo, Falun.
Between lake Storflaten and lake Van, Leksand.

To oxides index.
Mineral group index.
Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.

axelsson@acc.umu.se

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Last changed : 1998-06-17

Mineral class	Oxides : Rutil-cassiterite group.
Chemical formula	SnO₂
Crystal system	Tetragonal.
Habitus	Often as short prismatic crystals. Also as small grains or banded fibric masses.
Cleavage	Poor, fracture subconchoidal to uneven.
Hardness	6-7
Density	6.8-7.1
Color	Black, but also yellowish and colorless. Translucent to opaque.
Streak	White to weakly brownish.
Luster	Adamantine, greasy on fractures.
Description
Occurance	In pegmatites, high temperature hydrothermal veins and some metamorphic rocks.
Associates
Notes	Cassiterite is insoluble in acids and infusible.
Locations	A rare mineral in Sweden. Varuträsk, Västerbotten. Common as poorly developed crystals, streak color reddish brown. Utö, Stockholm. As small grains. Finnbo, Falun. Between lake Storflaten and lake Van, Leksand.