Or Something else is in the glaze kiln. The 23 x 27 Olympic kiln with computer controller just finished its 19th glaze firing to cone 6 oxidation. For most of those firings I have found small bits of something metallic in the bottom of 1 or 2 bowls or mugs. I think it is metallic. I scraped the trash in the bottom of the tumbler with a plastic handle and it cut the handle. This past firing, the tumbler was in the middle of a half shelf on the bottom. 2 other pots were closer to the wall with the