At first I thought that the bubbles were pretty cool—a foaming mass of red is pretty interesting visually—but as I began to question what was behind their presence, I also began to worry. It occurrs to me that although I carefully cleaned and oiled the tumbler’s machinery, I never thought to give its inside a good cleaning. I wonder if the bubbles are the result of a previous owner’s work … and what effect that might have on the pigment’s state and colour?
(This is where I really wish I had a good microscope to visually compare the pigment I’ve created in the past with my mortar and pestle with these results, and share a couple photos too.)
Although it’s not my focus for these experiments, the rocks themselves are also showing the effect of begin tumbled. Their sharp edges have been ground down and there are glossy spots beginning to appear. At least here their colours remain a very bright red …
I’m going to keep running the tumbler for another week and see what transpires; in the meantime I have some icon panels I need to finish for a couple upcoming iconographic works!