Re: last step of tumbling?
Cerium oxide is my polish of first resort for cabbing and faceting chalcedonies and glass. If you haven't tried cerium oxide as a polishing agent for your agatized coral and glass, you might want to give it a go.
I don't do much tumbling myself, but one piece of advice I hear repeatedly from tumbling experts is not to mix different materials in the same batch, particularly materials with different hardnesses. You didn't say if you are trying to tumble and polish glass and agatized coral together, but if you are and having problems, you might want to try separating them into different batches.
Good luck and once figured out, let us know what worked for you.
Keep on Rock'n!
From Bob Keller - March 26, 2011 at 09:50:38