Ceramics

ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. [1][2] Common examples are earthenware, porcelain, and brick.

The earliest ceramics made by humans were pottery objects (pots or vessels) or figurines made from clay, either by itself or mixed with other materials like silica, hardened and sintered in fire. Later, ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, amorphous ceramic coatings on top of the crystalline ceramic substrates.
Ceramics is one of the most ancient industries going back thousands of years. Once humans discovered that clay could be found in abundance and formed into objects by first mixing with water and then firing, a key industry was born. The oldest known ceramic artifact is dated as early as 28,000 BCE (BCE = Before Common Era), during the late Paleolithic period. It is a statuette of a woman, named the Venus of Dolní Věstonice, from a small prehistoric settlement near Brno, in the Czech Republic. In this location, hundreds of clay figurines representing Ice Age animals were also uncovered near the remains of a horseshoe-shaped kiln.

The first examples of pottery appeared in Eastern Asia several thousand years later. In the Xianrendong cave in China, fragments of pots dated to 18,000-17,000 BCE have been found. It is believed that from China the use of pottery successively spread to Japan and the Russian Far East region where archeologists have found shards of ceramic artifacts dating to 14,000 BCE.

Use of ceramics increased dramatically during the Neolithic period, with the establishment of settled communities dedicated to agriculture and farming. Starting approximately in 9,000 BCE, clay-based ceramics became popular as containers for water and food, art objects, tiles and bricks, and their use spread from Asia to the Middle East and Europe. The early products were just dried in the sun or fired at low temperature (below 1,000°C) in rudimentary kilns dug into the ground. Pottery was either monochrome or decorated by painting simple linear or geometric motifs.

It is known that, around 7,000 BCE, people were already using sharp tools made from obsidian, a natural occurring volcanic glass. The Roman historian Pliny reported that the first man-made glass was accidentally produced by Phoenician merchants in 5,000 BCE, when, while resting on a beach, they placed cooking pots on sodium-rich rocks near a fire. The heat from the fire melted the rocks and mixed them with the sand, forming molten glass.

Archeologists have not been able to confirm Pliny’s recount. Instead, simple glass items, such as beads, have been discovered in Mesopotamia and Egypt dating to 3,500 BCE. At the beginning of the Bronze Age, glazed pottery was produced in Mesopotamia. However, it was not until 1,500 BCE that Egyptians started building factories to create glassware for ointments and oils.

One of the first breakthroughs in the fabrication of ceramics was the invention of the wheel, in 3,500 BCE. The introduction of the wheel allowed for the utilization of the wheel-forming technique to produce ceramic artifacts with radial symmetry.

Meanwhile, ceramic pottery evolved in its use of increasingly elaborated paintings, so that these objects eventually became genuine pieces of art. Decorations also involved the use oxidizing and reducing atmosphere during firing to achieve special effects. Greek Attic vases of the 6th and 5th centuries BCE are considered the apex of this evolution.

Throughout the 16th century CE (CE = Common Era), earthenware remained the main class of ceramic products manufactured in Europe and the Middle East. The Chinese were the first to introduce high temperature kilns capable of reaching up to 1350°C, and, around 600 CE, developed porcelain (a material with less than 1% porosity) from kaolin clay. During the Middle Ages, trade through the Silk Road allowed for the introduction and diffusion of porcelain throughout Islamic countries first and later in Europe, due in large part to the journeys of Marco Polo.