Corundum- Corundum mineral is hard, durable and strong mineral. It is famous because ruby and sapphire gemstone are extracted from it.Corundum mineral comes in crystalline form of aluminium oxide along with traces of iron, titanium and chromium. Corundum is mainly used as abrasive in sandpaper.The gemstone extracted from corundum are sapphire and ruby are used for jewelry purposes and other stonesincluded are Burmese ruby, Mozambique ruby, star ruby, Ruby Glass Filled, Kashmir sapphire, Songea Sapphire. Deposits of corundum is available in Zimbawe, Russia, Sri Lanka, India, USA and Greek island.