ArizonaDave
Well-Known Member
From first hand experience, marbles wear away pretty quickly. I don't think I'd want to inhale anything that might have silica in it. If you do go with ceramic, run them for a few hours in whatever mill with water and then wash, rinse and dry. That will take off the loose pieces and sharp edges, after that, ceramic wears very slowly. Real bearing balls are not usually plated, neither is steel tumbling media.
With any silica it WILL scar the lungs!!!