Distinctive Faceted Slate Grey Crab Fire Agate Barrel Beads - Large 18mmPrice is per 15 inch string of 15 beads. Each bead measures 18mm x 13mm, drilled ready to thread. Beautifully faceted heavy. 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 concentric bands like the rings of a tree trunk. The