London Blue Topaz Rondelle Faceted Beads 5.5mm (10) 10 London Blue Topaz rondelle faceted beads 5mm diameter , ~3mm thick, Transparent gem quality, facets; all blue Topaz is treated for color 1 specified buys 10, 3 buys 30 beads, etc. Use very fine cord and wire, small holes, 0.012" 0.3mm