Beautiful Large Brazilian Agate Tube Beads - Natural!Price is per 15 inch string of these natural beads. Each measures around 17mm x 15mm about 20 beads to the string. As they are natural, all will be slightly different to picture. No gemstone is more creatively striped by nature than agate, chalcedony quartz that forms in concentric layers in a wide variety of colours and textures. Each individual agate forms by filling a cavity in host rock. As a result, agate often is found as a round nodule, with