This beautiful blue to teal green color-shift Umba sapphire is from our Moyo Gems Collection. It was responsibly sourced from TAWOMA (the Tanzanian Womens Mining Association) member, Mwanaidi, who mined the rough gemstone in Tanzania's Tanga region. The square emerald cut was faceted by Beth Stier in Michigan. Beth's cutting of this sapphire is fantastic, yet the internal charactaristics of the gem consistent with those Umbas are known for (rutiles and inclusions) that add character and life to the gem. Not eye clean. No heat. Untreated.