Crystalline glazes are an ancient process that developed back in the Sung Dynasty circa 960-1279 A.D., and gained popularity in the 1800’s in Europe. In the early 1900’s, American potteries, such as Rookwood, produced a form of crystalline that they termed, “The Tiger’s Eye” glaze. They are the most dazzling of electric-fire glazes.

Crystalline is the most challenging, yet the most rewarding, to produce. The crystals are grown on the surface around zinc oxide “seeds” contained in the glaze. Firing is achieved through high and low temperature fluctuations.

High temperatures turn the glaze into a molten state where many of the “seeds” dissolve. The temperature is then lowered where the remaining “seeds”, acting somewhat like magnets, attract the appropriate minerals in the glaze and the crystals grow on the seeds.
The crystals formed may be large or small, many or few, located evenly on the vessel or randomly. They have been likened to a snowflake or ghinko leaf appearance. Because of the high casualty factor and unpredictability, it is a very expensive process. A crystalline vessel is truly unique.

Crystalline glazes are an ancient process that developed back in the Sung Dynasty circa 960-1279 A.D., and gained popularity in the 1800’s in Europe. In the early 1900’s, American potteries, such as Rookwood, produced a form of crystalline that they termed, “The Tiger’s Eye” glaze. They are the most dazzling of electric-fire glazes.

Crystalline is the most challenging, yet the most rewarding, to produce. The crystals are grown on the surface around zinc oxide “seeds” contained in the glaze. Firing is achieved through high and low temperature fluctuations.

High temperatures turn the glaze into a molten state where many of the “seeds” dissolve. The temperature is then lowered where the remaining “seeds”, acting somewhat like magnets, attract the appropriate minerals in the glaze and the crystals grow on the seeds.
The crystals formed may be large or small, many or few, located evenly on the vessel or randomly. They have been likened to a snowflake or ghinko leaf appearance. Because of the high casualty factor and unpredictability, it is a very expensive process. A crystalline vessel is truly unique.