Ceramics are produced by heating natural earth until it changes form (without melting -- glasses are formed by earth heated until it melts and then cools).
Ceramics are different from merely dried earth or clay, which soften when rewet. Cements and plasters, although similar after hardening in some properties to ceramics, are produced by powdering a mineral and bonding the grains together with water. The high heat at which ceramics are produced drives off water chemically bound to the earth as well as any water that has soaked into it. The result of such heating, depending in part on the type of clay or earth, can be terra cotta, stoneware, china, porcelion, brick, or tile.
True ceramics appear rarely in nature, but are sometimes the result of lightning strikes and forest fires. From the control of fire by Homo erectus to the accidental production of ceramics is a very short step. Apparently, the deliberate production of ceramics had to wait until the more inventive Homo sapiens arrived on the scene.
At one time archaeologists believed that deliberate ceramics were a fairly recent discovery, 10,000 years old at the most. A popular theory was that basketry was invented first, but baskets do not hold liquids well. According to this theory, early people solved this problem by lining baskets with clay, which is impermeable. Sometimes baskets so lined got burned and the clay lining was left behind as a pot. Eventually, people found that they did not have to start with the basket. This theory is reminiscent of Charles Lamb's famous essay on the discovery of roast pig via burning down the house.
Ceramics may or may not precede basketry (which is, of course, biodegradable and easily lost from the archaeological record), but they certainly date much before 10,000 bce. Furthermore, ceramics were being deliberately made well before the first known ceramic pot. About 28,000 bce, in the region now known as the Czech Republic, people built kilns and produced small ceramic figures and beads. Ovens that may have been kilns as well go back another 14,000 years.
Practical ceramics -- pottery and brick -- start with the Neolithic Revolution. The first bricks, however, were not ceramics; they were adobe, clay or mud hardened by drying but without the chemically bound water driven off by heat. When kiln-dried bricks became available, the cost of making them resulted in their being reserved for special monumental buildings; the common people continued to build houses with sun-dried brick.
Pottery was shaped by hand during the Neolithic. Sometimes a large pot would be built and fired in sections that were then glued together with clay and fired again. The invention of the potter's wheel near the start of civilization was a great step, leading not only to better pottery but also to the general principle of the wheel for use in transportation and machinery.
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