Allochromatic gems are gems that happen to be colored by impurities. Whenever they have been entirely pure, they might be colorless. The color of all allochromatic gems is made by defects. As a result, all shade in corundum is because of defects. Known for its clarity and shading uniformity, the https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share