Formula: SnO2 simple oxide, rutile group
Specific gravity: 6.98 to 7.01
Hardness: 6 to 7
Streak: Brownish white, white, greyish
Colour: Black, yellow, brown, red or white.
Solubility: Slightly soluble in hydrochloric and nitric acid; insoluble in sulphuric acid
Plutonic igneous environments
Cassiterite is widely distributed. It occurs as a primary mineral in igneous
pegmatites but it is more commonly found as an unaltered
primary mineral in
hypothermal (high temperature) hydrothermal quartz veins of tin deposits in
granitic rocks. Because of its durability it is also found frequently in
In high temperature quartz veins associated with granitic intrusions cassiterite is often associated with ferberite, molybdenite and arsenopyrite.
At Llallague, Bolivia, cassiterite in hydrothermal veins crystallises at about 300oC.
Common impurities: Fe,Ta,Nb,Zn,W,Mn,Sc,Ge,In,Ga