This analyze of yellow sapphires was inspired by The dearth of clarity from the literature as towards the origin from the yellow coloration. Looking back, this uncertainty was the result of 3 aspects. To start with, the Fe3+ concentration in natural stones spans A variety of somewhere around four–4750 ppma, https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share