High-fired Japanese saturated iron glaze usually containing at least 10% (of dry-batch weight) iron oxide, which produces iridescent microcrystalline rust red. See kaki.

Japanese trimming tool, formed of a steel strap bent and sharpened on the ends.

  Al₂O₃—2SiO₂—2H₂O Primary clay that fires pure white, very refractory, coarse particle size, low plasticity, high-temperature major component of porcelain and some white ware bodies.  See EPK, Grolleg, Helmer, Tile-6.

Crystalline clay mineral forming the basis of most clays we use in ceramics.

Greek term meaning earthenware from which the word ceramics is derived.

In plaster slip-casting molds, small rounded depressions carved in each parting face of a mold segment, so that when adjacent segments are cast a corresponding bump will form. In use, the keys allow the mold segments to be aligned and assembled securely after the original prototype is removed. 

A specialized oven or furnace used for firing clay for pottery.

Refractory shelves, posts, and stilts used in a kiln to support the wares.

Automatic shutoff device mounted on many electric kilns; accepts a small-size pyrometric cone, and shuts off kiln when cone deforms.

Refractory slip coating applied to top surface of kiln shelf to protect from glaze runs. For all but salt and wood firings, 50-50 kaolin and silica. For salt and wood, 60% alumina, 30% kaolin, 10% ball clay.

In combustion of fuels, temperature that must be reached before oxidation reaction will produce enough heat to sustain and accelerate. For wood and paper, kindling temperature is 451° F.

Potash spar no longer mined. Substitute Custer or G-200.

Na₂O—Al₂O₃—6SiO₂ a common soda feldspar powerful HT alkaline flux. Toxic in inhalation.

3Al₂O₃—2SiO₂ aluminum silicate used in place of alumina and silica to promote formation of mullite crystals, increase thermal shock resistance. Coarse-ground used as grog in refractory bodies for kiln furniture.