This examine of yellow sapphires was enthusiastic by the lack of clarity from the literature as to the origin on the yellow coloration. On reflection, this uncertainty was the results of three aspects. Initially, the Fe3+ focus in natural stones spans An array of close to 4–4750 ppma, but only https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share