Creations in Crystalline Pottery

by Jan Pacifico







Crystal glazes are created by special forming, glazing and firing technique which are necessary in order to produce dazzling crystals on the pot's surface, reminiscent of flowers, frost or thistles blowing in the wind.


The pots are formed from porcelain clay, free from any impurities which can impede the growth of the crystals. In order for the crystals to grow, the glaze must be extremely fluid. This in turn, requires a pedestal fitted exactly to the base of the pot, which will capture any run-off of the fluid glaze. The post are fired to a high stoneware temperature and then cooled to a temperature beneficial to the growth of crystals. An overload of zinc in the glaze is responsible for crystallization in much the same way that rock candy results from a solution supersaturated with sugar. The temperature in the kiln is held steady for a period of 3-4 hours in a 100 degree range. The pots are then cooled normally. After cooling, the pedestal is sawed and chiseled to release it fom the bottom of the pot. The bottom is then ground smooth on a grinding wheel. Variations of glaze color can be achieved by dripping oil in the cooling kiln, using an intravenous drip bag which introduces oil through the tube inserted in the spy hole of the kiln. This process can turn green glazes into spectacular coppers and reds, similar to the exciting Japanese techniques of raku and hikidashi.