Allochromatic gems are gems which can be coloured by impurities. If they ended up totally pure, they might be colorless. The color of all allochromatic gems is made by defects. So, all color in corundum is because of defects. Therapeutic Positive aspects: The stone also provides many therapeutic benefits to https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share