Allochromatic gems are gems which have been colored by impurities. When they have been entirely pure, they would be colorless. The color of all allochromatic gems is made by defects. So, all coloration in corundum is a result of defects. Marital Bliss: Donning a natural Pukhraj will increase marital bliss. https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share