This examine of yellow sapphires was enthusiastic by the lack of clarity within the literature as into the origin with the yellow coloration. In retrospect, this uncertainty was the result of 3 factors. Very first, the Fe3+ focus in natural stones spans An array of around 4–4750 ppma, but only https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share