This review of yellow sapphires was motivated by The shortage of clarity in the literature as into the origin of your yellow coloration. On reflection, this uncertainty was the results of a few factors. To start with, the Fe3+ focus in natural stones spans An array of about 4–4750 ppma, https://worldlistpro.com/story19825903/the-definitive-guide-to-natural-yellow-sapphire-from-sri-lanka