Tanzanite was discovered in the Mererani Hills in northern Tanzania. Tanzanite is a 6.5 on the Mohs scale. This stone shows a very unique dichroic effect with a greenish-blue hue from the front and back but changing to a light brownish color when turned to the sides, weighs 5.93 cts. and measures 13X6X6 mm. This color difference is truly one of the qualities that make Tanzanite such an amazing stone. This rough has no known treatments. These pictures are not to scale so please read each description for the actual size.