Pottery

Earthenware fires below about 2,100°F and stays porous. Stoneware fires above that and vitrifies — the clay body partially melts into a glassy, watertight material. The temperature difference is roughly 200°F. What it changes about the resulting object is almost everything.

Burnishing is the process of polishing leather-hard clay with a smooth tool until the surface compresses and begins to reflect light. No glaze is involved. The shine comes from the clay itself, and it survives firing to produce a surface that has been valued for ten thousand years.

Pit firing is the oldest firing method for ceramics. A hole is dug, pots are stacked inside with combustible material, the pit is lit and covered. What emerges, after hours of burning and cooling, carries flame markings, carbon flash, and the colors of whatever was in the pit with it.