This study of yellow sapphires was inspired by The shortage of clarity within the literature as towards the origin of the yellow coloration. In retrospect, this uncertainty was the results of 3 aspects. 1st, the Fe3+ focus in natural stones spans A variety of close to four–4750 ppma, but only https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share