This research of yellow sapphires was inspired by The shortage of clarity in the literature as into the origin from the yellow coloration. Looking back, this uncertainty was the results of three elements. First, the Fe3+ concentration in natural stones spans A variety of about 4–4750 ppma, but only concentrations https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share