Corundum is a relatively common mineral that once found wide application as an industrial abrasive. Gem corundum is mined almost exclusively from gem gravel deposits. These deposits are derived from the weathering of high temperature metamorphic (marble, gneiss) or igneous (volcanic or pegmatitic) source terrains. Historically, the most famous and prolific production has been from Myanmar (Burma), Thailand, India, Afghanistan, Pakistan, and Sri Lanka (Ceylon). More recent important sources include Australia and the East African countries of Tanzania and Kenya.