This study of yellow sapphires was enthusiastic by the lack of clarity in the literature as for the origin of the yellow coloration. Looking back, this uncertainty was the results of three aspects. 1st, the Fe3+ focus in natural stones spans a range of roughly four–4750 ppma, but only concentrations https://thebookmarkid.com/story18170320/not-known-facts-about-natural-yellow-sapphire-from-sri-lanka