This research of yellow sapphires was inspired by the lack of clarity from the literature as towards the origin with the yellow coloration. Looking back, this uncertainty was the results of a few elements. 1st, the Fe3+ concentration in natural stones spans A variety of close to 4–4750 ppma, but https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share