Ceramic

A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling.

Ceramic materials may have a crystalline or partly crystalline structure, or may be a glass.

Ceramic materials may have a crystalline or partly crystalline structure, or may be a glass.

The earliest ceramics were pottery objects or 27,000 year old figurines made from clay, either by itself or mixed with other materials, hardened in fire.

The earliest ceramics were pottery objects or 27,000 year old figurines made from clay, either by itself or mixed with other materials, hardened in fire.

Later ceramics were glazed and fired to create a colored, smooth surface.

Later ceramics were glazed and fired to create a colored, smooth surface.

Later ceramics were glazed and fired to create a colored, smooth surface.

Later ceramics were glazed and fired to create a colored, smooth surface.

Ceramics now include domestic, industrial and building products and art objects.

Ceramics now include domestic, industrial and building products and art objects.

Ceramic materials are brittle, hard, strong in compression, weak in shearing and tension.

Ceramic materials are brittle, hard, strong in compression, weak in shearing and tension.

They withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments.

They withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments.

Ceramics generally can withstand very high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C (1,800 °F to 3,000 °F).

However, glass making involves several steps of the ceramic process and its mechanical properties are similar to ceramic materials.

Methods for dealing with them tend to fall into one of two categories – either make the ceramic in the desired shape, by reaction in situ, or by "forming" powders into the desired shape, and then sintering to form a solid body. Ceramic forming techniques include shaping by hand (sometimes including a rotation process called "throwing"), slip casting, tape casting (used for making very thin ceramic capacitors, e.g.), injection molding, dry pressing, and other variations.

Methods for dealing with them tend to fall into one of two categories – either make the ceramic in the desired shape, by reaction in situ, or by "forming" powders into the desired shape, and then sintering to form a solid body. Ceramic forming techniques include shaping by hand (sometimes including a rotation process called "throwing"), slip casting, tape casting (used for making very thin ceramic capacitors, e.g.), injection molding, dry pressing, and other variations.

Noncrystalline ceramics, being glasses, tend to be formed from melts.

The glass is shaped when either fully molten, by casting, or when in a state of toffee-like viscosity, by methods such as blowing to a mold.

Ceramics in archaeology

Ceramic artifacts are an important role in archaeology for understanding the culture, technology and behavior of peoples of the past.

They are among the most common artifacts to be found at an archaeological site, generally in the form of small fragments of broken pottery called sherds.

Traditional analysis involves sorting ceramic artifacts, sherds and larger fragments into specific types based on style, composition, manufacturing and morphology.

Temper is usually identified by microscopic examination of the temper material.

Clay identification is determined by a process of refiring the ceramic, and assigning a color to it using Munsell Soil Color notation.