Allochromatic gems are gems that happen to be colored by impurities. When they were being fully pure, they would be colorless. The color of all allochromatic gems is produced by defects. As a result, all color in corundum is caused by defects. By subtracting various quantities of the h•-Fe3+ absorption https://mysocialguides.com/story3411815/sri-lankan-yellow-sapphire-for-dummies