Sapphires are a variety of the mineral corundum that come in many colors, most commonly blue, yellow, and pink. They form in locations around the world, and have been mined using different techniques from traditional pit mining done by hand to larger open pit and open cast mining done with machinery. The Logan Sapphire found in Sri Lanka is one of the largest ever at 422.99 carats. Major sources of sapphires have included Burma, Sri Lanka, Madagascar, and Australia.