This examine of yellow sapphires was enthusiastic by The shortage of clarity inside the literature as on the origin from the yellow coloration. Looking back, this uncertainty was the result of a few components. To start with, the Fe3+ focus in natural stones spans An array of about four–4750 ppma, https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share