Amethyst is a purple variation of quartz that owes its beautiful coloration to iron impurities, and the presence of trace elements. Amethyst is a 7 on the Mohs scale. This particular Rwandan piece weighs 49.90 cts. and measures 33x18x13 mm, and exhibits that beautiful rich purple color that Amethyst is usually known for. These pictures are not to scale so please read each description for the actual size. This piece may have been heated.