Cassiterite is a tin oxide mineral with a chemical composition of SnO2. It is the most important source of tin, and most of the world's supply of tin is obtained by mining Cassiterite. Small amounts of primary cassiterite are found in igneous and metamorphic rocks throughout the world. It is also a residual mineral found in soils and sediments. Cassiterite is more resistant to weathering that many other minerals, and that causes it to be concetrated in stream and shoreline sediments. Color: black, brownish black, reddish brown, brown red, yellow, gray, white: rarely colorless. Composition: 1. Tin (Sn) Min: 72.00 Max: 92.00 2. Sicile (SiO2) Min: 5.00 Max: 10.00 3. Tentalite (Fe2 + Ta2O6) Min: 1.00 Max: 3.00 4. Iron (Fe): Min: 0.01 Max: 0.10 5. Granulometric: Min: 1/8" Max: 1" 6. Density (gh/cm3) Min: 6.98 Max: 7.01 7. No Radioactive elements 8. No thorium 9. No Uranium Sales prices will be based on LME: London Metal Exchange. Price LME / 100% of purity. An additional discount of 10% above final price after test.