Garnets are a group of silicate minerals, Garnet forms when a sedimentary rock with high aluminum content, such as shale, is metamorphosed. Garnet has a hardness of 6.5 to 7.5 on the Mohs scale. This piece of Lindi Garnet rough from Tanzania weighs 2.89 cts., measures 8x6x6 mm. and has a small veil on the edge that can be cut out in preform. Currently available at New Era Gems.