This research of yellow sapphires was determined by The dearth of clarity within the literature as into the origin in the yellow coloration. Looking back, this uncertainty was the result of 3 factors. 1st, the Fe3+ focus in natural stones spans An array of close to four–4750 ppma, but only https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share