My periodic table poster is now available! Cassiterite. Description from the source: Cassiterite (Sn O2 tet.), Huanuni, Bolivia. Crystal cluster with Pyrite. 2,5x2x1,6 cm; 20 g. Source: Simone Citon Contributor: John Gray Acquired: 30 September, 2008 Text Updated: 1 October, 2008 Price: Trade Size: 1" Composition: SnO2