Sapphire, whether from Sri Lanka, Madagascar, Thailand, Africa, or Montana US, all have the same chemical composition - they’re all corundums. The difference lies in their growing environments and the trace elements present during their formation. Quality characteristics such as color and saturation, sparkle or “life”, cut and color modifiers help us determine a sapphire’s country of ...
https://www.marketsquarejewelers.com/blogs/msj-handbook/sources-for-sapphire-gemstones...