Morado Agate has a nice purple color under the white rind!
Agate is a form of microcrystaline quartz. It is usually formed in nodules and has transparent, or translucent portions. As with all of the other species in the quartz family, agate takes a high polish with cerium oxide, but also takes a fine polish with tin oxide and diamond. Mohs hardness 6.5 to 7.