Large Polished Moss Agate Prism Beads - Unusual, Large 30mm!Price is per 16 inch string of these beautiful beads each measures a large 30mm x 16mm x 8mm, about 13 beads to the string. As they are natural, colour & pattern will be slightly different on each bead. What is agate? Agate is nature's most striped gemstone. A variety of microcrystalline quartz that forms in layers and many colours and texture, by filling a cavity in a host rock although it is usually in round nodules with bands looking like eyes in