12.5" wide x 3.5" high
Arrested bubbling of molten mud erupting through crystalline surface. What does this say about the deeper layers of Earth? A fractal thinker could spin a story; a logical geologist said, "That's subduction". If you're prone to staring at natural evidence, you might be intrigued.
Exterior is same glaze as interior applied thinkly, showing foraminfera speckles. Rim glaze assembled from refined materials.