This review of yellow sapphires was inspired by the lack of clarity in the literature as to the origin in the yellow coloration. Looking back, this uncertainty was the result of 3 components. To start with, the Fe3+ focus in natural stones spans An array of close to four–4750 ppma, https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share