This is a 2mm non-abrasive Ceramic media. These can be used when tumbling rock to act as a polish carrier and filler to aid in polishing of the stones in the tumbler.  They are 2mm round ceramic balls and are used only in polishing.

These can work wonders on soft materials such as Petosky stones, onyx, turquoise, marble etc…  They work mainly in Rotary tumblers.   Info on their use can be found in our “Polishing soft stones” link.