Allochromatic gems are gems which are colored by impurities. Should they ended up entirely pure, they might be colorless. The color of all allochromatic gems is made by defects. So, all colour in corundum is a result of defects. The Srilankan Yellow Sapphire gemstone escalates the comprehension and harmony in https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share