Fundamental Rockhound Products: 5 lb Mixed Ceramic Tumbling Media for Rock Filler, Cushioning, Protecting Five pounds mixed white ceramic media for rock tumbling. Used to cushion stones, carry slurry, protect delicate stones, carry polish, or use as a filler. Sizes are large: 5/8" X 3/8"; small 3/8" X 3/16" angle cut Each pound measures slightly more than one measuring cup Please see description for more detailed information ****WARNING**** There are always a few sharp edges when brand new. If using this media for the fine or polish stage, run for a few days in water in the tumbler to smooth off the sharp edges or you could scratch your stones.