Ancient process marks clay with fire: Glossary of terms
Ceramics Terms
Biscuit /Bisque -- an unglazed piece of earthenware, stoneware or porcelain that has been fired once.
Body -- unfired pottery -- the name given to the composite materials of which potter’s clay is made. The term "body" is generally used when referring to earthenware or stoneware.
Ceramics -- a term which covers all objects of clay that have been hardened by fire. The word comes from the Greek keramos meaning potter’s clay. The clay can be shaped by one of three methods -- mold, coil or thrown on a wheel.
Flux -- a substance added to ceramics and glazes which lowers their melting point. Often used to fuse over glaze pigments to the glaze.
Glaze -- a shiny non--porous coating on pottery and porcelain. A thin coating is applied to ceramic bodies to make them impervious to liquid absorption and for decorative purposes.
Grog -- small pieces of crushed pottery or fired clay sometimes added to the primary fabric for strength or applied to a vessel’s surface as decoration.
Hand-build -- a technique for making pottery using slabs or coils of clay.
Hollow ware -- pots, jugs, mugs or bowls made on a potter’s wheel.
Kiln -- the oven in which ceramics are fired.
Oxidizing -- referring to the oxygen atmosphere inside a kiln during firing, which causes color changes due to chemical reactions in the glaze or body. For example, fine stoneware fired in an oxygen atmosphere can be turned brick red, while the same clay fired in a reducing atmosphere can be colored black.
Potter’s wheel -- a rotating horizontal disk, mounted on a vertical shaft and turned by foot or a motor, upon which clay is molded into bowls or pots.
Reduction -- the absence of oxygen in the atmosphere of a kiln during firing. The lack of oxygen can affect color in glaze or body.
Salt glaze -- a high temperature glaze which is formed by the addition of common salt into the kiln when it is at the highest temperature. The vaporized sodium combines with the silica on the surface of the vessel to create a glossy, hard glaze. Salt glazes are characterized by a pitted "orange peel" texture and are only used on stonewares.
Slip -- diluted wet clay, used to stick handles, etc. on to the body of a pot. Potter’s clay reduced to a liquid batter, used for coating, or decorating pottery.
Vitreous stoneware -- earthenware that does not need glazing. It is fired at higher temperatures than pottery and has a hard impervious surface.
Source: http://www.crackedchina.co.uk/glossary.htm (Bad URL perserved for history)