Allochromatic gems are gems that happen to be coloured by impurities. When they have been entirely pure, they'd be colorless. The color of all allochromatic gems is made by defects. As a result, all colour in corundum is a result of defects. Delhi is the leading location for gem lovers, https://bookmarkstime.com/story18434628/considerations-to-know-about-sri-lankan-pukhraj