Allochromatic gems are gems that happen to be colored by impurities. Should they have been totally pure, they might be colorless. The colour of all allochromatic gems is made by defects. So, all coloration in corundum is due to defects. Natural Pukhraj can be a extremely coveted and precious gemstone, https://trackbookmark.com/story19507312/new-step-by-step-map-for-natural-pukhraj-from-sri-lanka