SiO2>99.31%,Fe2O3<0.018% Hardness>8,higher than French pebbles Our own silica mine and factory Silica pebbles manufacturer 1. About Silica pebbles / Flint pebblesName: Silica pebblesOther names: Flint pebbles, Silica grinding pebbles, Silica grinding ballsProperty: Round gray-white silica stoneSize: 2-4cm, 4-6cm, 6-8cm, 8-10cm, 10-12cm, 12-15cmApplication: Silica pebbles can be used as grinding ...