Amber is a organic gemstone. So amber doesn't have crystalline structure like most gemstones instead it is created through biological processes either from animal or plant. Amber is not the only organic gemstone other organic gemstones would include coral , jet , ivory , and pearl . Amber is amorphous not crystalline. Amber is presented in colors yellow, orange, and brown. But some blue ambers have been found though they are pretty rare. On the mohs hardness scale it is scaled at being not that hard around 2 to 2.5. It's fairly light having a density of 1.05 to 1.09. It is found in the Baltic region.