Clay that has been fashioned into a desired shape and then dried to reduce its water content before being fired or baked to fix its form. At temperatures of about 400 °C water begins to be lost from the molecules forming the clay and at this point the clay cannot be returned to a plastic state through rehydration. At around 1000 °C the clay molecules begin to fuse, and at higher temperatures still the minerals vitrify into a solid mass.
Pottery is made in many different ways either by hand or using a potter's wheel. Because of the widespread availability of usable clay, pottery was independently invented in many parts of the world at different times.