The surface defect appeared mainly as air bubbles and ferroferric oxide drops which centred around the lower outer - field portion of the stoneware cup.
This material here allowed us to create something specifically fire resistant, because it's glass actually, and above it, you won't believe it, but it's large format porcelain stoneware.
As you can see, this is thin porcelain stoneware, it has very complex angles, only 90 degrees, and in order to technically implement them well, we cut them at 45 degrees.
The fact that early American stoneware is bound up with industrial slavery, a lesser-known model than the agricultural kind, may be news to visitors at a major exhibition of David Drake's jars.
So we are going to go outside now, go get some even bigger reactions, with the alkali metals. This is a dog bowl which is stoneware, it is very hard, not likely to break, unless I drop it on my toes.