Corundum
Corundum is a crystalline form of aluminium oxide typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is also a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Ruby and Sapphire are examples of Corundum.
Corundum Can be found in South Africa, Namibia, Zimbabwe, Botswana and Swaziland.
Chemical Formular : Al2O3
Refractive Index : 1.767–1.772
Hardness : 8-9 on the Mohs Scale
Crystal System : Trigonal
