This study of yellow sapphires was determined by The dearth of clarity while in the literature as for the origin from the yellow coloration. In retrospect, this uncertainty was the results of a few aspects. Initially, the Fe3+ concentration in natural stones spans An array of somewhere around 4–4750 ppma, https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share