Large Hole Beads (Greek Ceramic Beads, glazed Sapphire): Ceramic tubes, glazed Sapphire, 6mm x 17mm. These ceramic beads in glazed Sapphire are exceptionally hard wearing due to the high temperature used when firing the glazed Sapphire color onto the ceramic base. In addition ceramic beads are very heavy and impossible to break. These beads are very individually shaped--not for perfectionists.