This analyze of yellow sapphires was motivated by the lack of clarity within the literature as to the origin from the yellow coloration. Looking back, this uncertainty was the result of 3 variables. First, the Fe3+ focus in natural stones spans A variety of close to four–4750 ppma, but only https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share