biscuit: also called bisque, unglazed porcelain or earthenware, fired once.
bone china: one of three kinds of porcelain, made of two parts bone ash, one part kaolin and one part feldspathic rock (china rock or petunse).
ceramic: an inorganic, non-metallic solid processed by the action of heat and subsequent cooling. Used in domestic, industrial or building products, art objects, and new ceramic materials developed in the twentieth century for specialized uses (heat resistant tiles on re-entry vehicles, semiconductors). Divided into four sectors: structural (bricks, roof tiles, etc), refractories (kiln lines, crucibles for steel or glass making), whitewares (wall tiles, tableware, bathroom fixtures, etc), and technical (which may not actually include clay in makeup: Space Shuttle tiles, gas burner nozzles, ballistic protection, bio-medical implants, jet engine turbine blades, etc). Whiteware includes earthenware, stoneware, porcelain and bone china. Glass is a non-crystalline ceramic. Shaped by hand forming, include throwing, slip casting, tape casting, injection molding, dry pressing or some combination of these processes.
china: term loosely used for porcelain.
clay: a naturally occurring material composed of fine-grain minerals, showing plasticity and can be hardened by drying or firing. Organic material may be included.
creamware: yellowish, lead-glazed earthenware developed by English pottery firms in mid-eighteenth century.
earthenware: made of roughly equal portions of clay, kaolin, quartz and feldspar. Bisque fired at 1000-1150 degrees C, 1800-2100 degrees F, and glaze fired at 950-1050 degree C, 1750-1925 degrees F. (may be reversed if desired) fired at lower temps, not impervious to liquids unless glazed. It is more easily chipped than bone china or porcelain. Less strong, less tough and more porous than stoneware, easier to work, costs less. Types of earthenware: creamware, delftware, faience, tin-glazed pottery, Victorian majolica, raku, terracotta.
faience (2 meanings): tin-glazed pottery from northern Italy (Faenza) or ancient ceramic beads with a glaze, found in Egypt and older civilizations: Minoan, Indus Valley. Types of European faience: Delftware, Quimper, majolica. Made by various firms in various European countries since the Renaissance, and in the US in the twentieth century.
flatware: plates, saucers, platters as opposed to cups, tureens, etc.
glaze: form of glass which becomes smooth and hard after firing, translucent to opaque, renders surface impermeable.
ground: base or background color, usually monochrome.
hard-paste porcelain: one of three kinds of porcelain, made of kaolinite, quartz (silica) and alabaster (or feldspar), and is fired at over 1230 degrees C, 2460 degrees F. It is hard and strong. This form is also called true porcelain.
kaolin (kaolinite): a form of aluminum silicate, a fine white clay mineral made up of aluminum, silicon, oxygen and hydrogen. Rocks rich in kaolinite are called china clay or kaolin.
parian: white bisque porcelain intended to resemble marble.
porcelain: ceramic material made of kaolin (kaolinite) and petuntse. It is hard, impermeable before glazing, translucent when thin, and inelastic, white unless colored on purpose. Porcelain has a high resistance to electricity, a attribute used in industrial applications. Three categories of porcelain: hard-paste, soft-paste, bone.
pottery: ceramic ware made by potters. earthenware, stoneware, porcelain. Clay formed into shape, fired to induce reactions that produce permanent changes: increased strength, hardening, setting of shape.
soft-paste porcelain: one of three kinds of porcelain, made of kaolin (china clay), frit (ground-up glass), soapstone and lime. It is also called artificial porcelain, and was developed in England c. 1750 to compete with Chinese hard-paste porcelain.
stoneware: made from clays that result in dense, impermeable, and hard (resisting scratching by a steel point) wares. Fired at 1200-1315 degrees C. (2192-2399 degrees F.), vitrifying the clay body. Stoneware is usually colored by by impurities in clay, resulting in a gray or brown ground. Stoneware may be glazed after one firing or glazed and fired in one firing. Porcelain is a type of stone ware.
soapstone: a form of steatite, used to replace kaolin in porcelain formulas to produce wares that can withstand changes in temperature.
terracotta: clay based unglazed ceramics that are not waterproof if unglazed. The color is usually some shade of orange, but can be yellow, gray and pink. A common material for bricks, tiles, water pipes, etc.
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Synopsis:
Ceramic encompasses all clay-based items processed through fire into items that retain the shape they were given prior to firing and can support their own weight. A subset of ceramics is pottery, which includes two types:
- earthenware: creamware, delftware, faience, tin-glazed pottery, Victorian majolica, raku, terracotta. Must be glazed to become impermeable.
- stoneware: heated to vitrification (impermeable without being glazed), includes porcelain (hard-paste, soft-paste and bone china).
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These definitions are a compendium of those in Wikipedia and those in Sotheby’s Concise Encyclopedia of Porcelain, ed. David Battie, Chancellor Press, 1998