Allochromatic gems are gems which might be colored by impurities. Whenever they had been wholly pure, they'd be colorless. The color of all allochromatic gems is produced by defects. Consequently, all shade in corundum is because of defects. It will eventually pretty much get eons to state each of the https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share