A gorgeous gem crystal of natural green-yellow Tanzanite (Zoisite) rarely seen from the Merelani gem Tanzanite deposits, although everybody is familiar with their blue cousins in quantity now. These are unique to this mining deposit, and only 1 in 1000 tanzanites has this special color. This brilliantly lustrous, gemmy, "yellow tanzanite" comes only rarely from these famous mines for blue Tanzanite. The color on these, at their best like this one, is really more like a classic 1940's Brazilianite than any other Zoisite (Tanzanite is itself a variety of the rock forming species Zoisite), and the tetragonal prism is key to its identification for those who have not seen these yet. This robust, 16 gram crystal exhibits sharp edges and crystal faces with a perfect termination! The details of the crystal are incredible: there are interesting horizontal striations on one set of prism faces, light vertical striations on the two opposing prism faces with delicate striations and stepped growth on the terminal faces. This is in the top percentile for quality for Zoisite/Yellow Tanzanite crystals and for the species. This is a perfect toenail and is also complete and pristine all around. Formerly on loan to the Zhejiang Museum of Nature and Science in Hangzhou, China, for their gem crystals exhibition in 2019.