Product specification Coated can be done from 50��m-1180��m, based on clients requirements. �� Technical references Appearance: beads with round ball shape and no visible impurity. Refractive index:��1.5 density:2.4-2.6g/cm3 SiO2 content:��68% size distribution and spherical beads. Water resistance: when the wastage of 0.1N hydrochloric acid is 10ml, the surface of glass bead does not fade. Coated feature: After soaking in water for 30 seconds and dry for 2 hours under in-door temperature, they can easily pass through filler while shaking slightly.