This research of yellow sapphires was determined by The dearth of clarity while in the literature as into the origin of the yellow coloration. In retrospect, this uncertainty was the results of a few aspects. 1st, the Fe3+ focus in natural stones spans A variety of around 4–4750 ppma, but https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share