Allochromatic gems are gems which have been coloured by impurities. When they have been totally pure, they might be colorless. The color of all allochromatic gems is made by defects. Therefore, all coloration in corundum is attributable to defects. Sri Lanka’s Competitive Gain Sri Lanka’s gem and jewellery value chain https://bookmarkstumble.com/story19678803/top-guidelines-of-sri-lankan-yellow-sapphire