An example of how cobalt can precipitate in a fluid melt glaze at cone 6

This glaze has a significant amount of cobalt carbonate and during cooling the excess is precipitating out into pink crystals during cooling in the kiln. This effect is unwanted because in this case since it produces an unpleasant surface and color (the photo does not clearly show how pink it is). This problem can be fixed by a combination of cooling the kiln faster, increasing the Al₂O₃ content in the glaze (it stiffens the melt and prevents crystal growth) or firing lower.

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Materials	Cobalt Carbonate
Glossary	Fluid Melt Glazes Fluid melt glazes and over-melting, over fired, to the point that they run down off ware. This feature enables the development of super-floss and cyrstallization.
Glossary	Crystallization Ceramic glazes form crystals on cooling if the chemistry is right and the rate of cool is slow enough to permit molecular movement to the preferred orientation.

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