This research of yellow sapphires was determined by The dearth of clarity inside the literature as into the origin from the yellow coloration. In retrospect, this uncertainty was the result of a few things. Very first, the Fe3+ concentration in natural stones spans A selection of approximately 4–4750 ppma, but https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share