Multi-gemstone Plain Rondelles measure approximately 3.5mm in diameter, the beads have a glassy luster on transparent bodies, the brilliance is high on these eye clean gemstones, these multi-gemstone beads have great polish with consistent depth, and the gemstones found in this strand are Rhodolite Garnet, Andalusite, Mandarin Garnet, Iolite and Quartz. The hole size is approximately .5mm. 26-28 guage wire is what is recommended when stringing these lovely gemstone beads.