Ceramic Products: A Brief Introduction
The earliest ceramics were pottery objects of 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. Ceramics now include domestic, industrial and building products and art objects. In the 20th century, new ceramic materials were developed for use in advanced ceramic engineering.
Nowadays, ceramic products are usually divided into four sectors: structural, refractory, technical and whitewares.
Whiteware ceramics tend to have both a functional and a decorative purpose. This product group includes products such as: statuettes, ornaments, animal figurines, parts for lamps, candle-holders, desk sets, plates, pottery, (fruit) bowls, vases, flower pots, etc. Ceramics, especially pots and to a lesser extent statuettes, are also frequently used to decorate the gardens, terraces or sunroofs. Some whiteware ceramic products are regarded as fine art, while others are regarded as decorative, industrial or applied art objects, or as artifacts in archaeology.
Materials to make whiteware ceramics include:
Earthenware, is a common ceramic material, which is used extensively for pottery tableware and decorative objects. Although body formulations vary between countries and even between individual makers, a generic composition is 25% ball clay, 28% kaolin, 32% quartz and 15% feldspar. Earthenware is one of the oldest materials used in pottery. After firing the body is porous and opaque, and depending on the raw materials used will be colored from white to buff to red.
Stoneware, according to the Combined Nomenclature of the European Communities, is dense, impermeable and hard enough to resist scratching by a steel point, differs from porcelain because it is more opaque, and normally only partially vitrified. It may be vitreous or semi-vitreous. It is usually colored grey or brownish because of impurities in the clay used for its manufacture, and is normally glazed.
Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between 1,200 °C (2,192 °F) and 1,400 °C (2,552 °F). The toughness, strength, and translucence of porcelain arise mainly from the formation of glass and the mineral mullite within the fired body at these high temperatures.
Bone china is a type of soft-paste porcelain that is composed of bone ash, feldspathic material and kaolin. It has been defined as ware with a translucent body containing a minimum of 30% of phosphate derived from animal bone and calculated calcium phosphate. Developed by English potter Josiah Spode, bone china is known for its high levels of whiteness and translucency, and very high mechanical strength and chip resistance.