... , nature and superior quality various gravel pebble stone1.material:natural stone(granite,marble,sandstone,quartz etc) directly from native quarry2. Specification ... :3-5mm,5-8mm,0.8-1 .5 cm; 2-4cm; 3-5cm; 4-6cm; 8-10cm; 10-15cm ... ensure your construction period9.These pebbles are made of natural stone, which are environmentally-friendly, ecological and non-toxic Tianyuan Brand ...