Ceramics and Civilization
Ceramic production is one of civilizations oldest crafts, dating back thousands of years when humans first discovered that clay mixed with water could be formed into objects and fired in rudimentary kilns to create figurines representing their physical environment then later finding practical applications for use in domestic life.
The oldest ceramic artifact found to date is thought to be about 28,000 BCE (Before Common Era), in the late Paleolithic Period. Known as Venus of Dolnί Vӗstonice, the statuette of a nude woman was found in a small prehistoric settlement near Brno, in the Czech Republic. Hundreds of clay figurines representing Ice Age animals were also found in this location along with a horse-shoe shaped kiln.
Pottery utensils appeared in Eastern Asia thousands of years later. In a cave in Xianrendong China, fragments of pots dating 18,000 – 17,000 BCE were found. The use of pottery successfully spread to Russia’s Far East where archaeologists have found shards of ceramics dating to 14,000 BCE.
There is evidence that use of ceramics increased dramatically during the Neolithic period (9,000 BCE) with the establishment of farming settlements. Clay ceramics became popular as containers for food and liquids. They were used as objects of art, for shelter, for making tiles and bricks and their use spread from Asia to Europe and the Middle East. Early examples were sun-dried or fired at low temperature in crude kilns dug into the ground.
A pivotal breakthrough in the history of ceramics was the invention of the wheel in around 3,500 BCE. This allowed for wheel-forming techniques that produced ceramics with radial symmetry. Decorations were enhanced by oxidizing and reducing atmosphere during firing to achieve special effects. Greek Attic vases of the 6th and 5th centuries BCE are considered the peak of this innovation. The Greeks developed by far the most sophisticated early pottery perfecting the decorative style known as black-figure and then introducing the red-figure technique. The Attic potters of the 6th century produced an attractive undercoated surface to their pots using red ochre in the clay.
Greek vases were made in more than a dozen standard shapes, each with a specific purpose. Used for storing wine or olive oil, for heating or cooling liquids, for pouring and drinking. The vases were intricately decorated with scenes depicting daily life or with tales of their Gods, Goddesses and heroes.
All these pots had one major disadvantage because fired earthenware is tough but porous. Liquid will soak into it and eventually leak through it. The solution was glaze, a substance applied to the inner or outer surface of an unfired pot, which vitrifies in the kiln forming a glassy skin that fuses with the earthenware to make it non-porous.
Glazed pots made their appearance in the Middle East in about the 1st century BC, possibly having been developed first in Egypt. The glaze was made from a composition of quartz, soda and a mineral containing copper which when fired covered the pot with a glass-like surface. The characteristic colour is bluish-green derived from the copper in the glaze. This pottery was common in imperial Rome but at this time glazed pottery was also being manufactured in the Han Dynasty, China, possibly due to the Silk Road connecting the two empires.
The Chinese introduced high temperature kilns capable of reaching up to 1350˚C, then around 600 BCE developed porcelain from kaolin clay, a material with less than 1% porosity. During the Middle Ages this method spread to Islamic countries via the Silk Road and later to Europe thanks to the journeys of Marco Polo. In Medieval times sand was mixed with clay to make cooking pots strong enough to be placed over an open fire.
In the 15th Century blast furnaces were developed in Europe, capable of reaching up to 1,500˚C. Since then, the ceramics industry has gone through a revolutionary transformation with much of the commercial earthenware produced in the second half of the 20th century being both heat and cold-proof and able to be used for cooking, freezing as well as serving.
Types of Ceramics
There are three main types of ceramic-ware;
Earthenware, Stoneware and Porcelain
Earthenware is the oldest and easiest type of pottery. It is also the softest, being heated at the lowest temperature, between 1000 and 2000 degrees Celsius. Stoneware is a denser type of pottery that is fired at a higher temperature, between 1100 and 1300 degrees Celsius. Typically, stoneware is coated with a glaze of powdered glass and fired again at a higher temperature creating a vitreous, impermeable surface. Where earthenware usually ranges in colour from light brownish, yellow to dark red, stoneware varies from grey to buff or even green. Porcelain remains the finest and most valuable variant, is finer than stoneware, makes a ringing tone when tapped and has a characteristic translucence when held up to the light.
Pottery can be glazed, using a range of mineral-based colour pigments. The addition of iron oxide, for instance, creates the greenish-coloured glaze characteristic of Chinese celadon pottery. It can also be hand-painted before or after glazing, a method known as underglaze (or overglaze) decoration. Slip painting is another decorative technique whereby a thin combination of water and clay, called slip, is applied to the surface like paint. Engraving or incising patterns in the clay can also be applied to the outer surface of the pot by wrapping the vessel in a mould or with coiled basketry, or by stamping patterns on the raw clay body.
Venus of Dolnί Vӗstonice
Pottery images from the Archaeological Museum of Olympia, Greece