The final stage of the pottery process moves away from geology and enters the realm of chemistry: Glazing. A ceramic glaze is not simply paint; it is a complex liquid mixture of minerals—primarily silica (glass former), flux (to lower the melting point), and alumina (to stiffen the glaze and keep it from running off the pot). When applied to the highly porous bisque ware, the pot instantly drinks up the water, leaving a powdery coat of raw minerals stuck to its surface. The glazed pottery is then loaded back into the kiln for the final glaze firing, which reaches much higher temperatures—often between 1200°C and 1300°C for stoneware or porcelain. As the heat builds, a profound transformation occurs: The powdery mineral layer melts, flows, and fuses into a smooth, liquid layer of colored glass. The clay body undergoes vitrification, where the remaining pores are completely filled with liquid glass elements, welding the clay particles into an incredibly dense, waterproof, and rock-hard structure. The raw minerals in the glaze chemically bond directly with the underlying clay body, forming an unbreakable interface. When the kiln finally cools down, the transformation is complete. The dull, fragile clay that came out of the earth has been permanently altered by chemistry and extreme heat into a vibrant, glassy, and completely functional ceramic piece designed to last for centuries.
