Mayco CG785 Royal Fantasy Jungle Gem Glaze, 4 oz Decorating Accessories and it is caused by

and it is caused by lithium carbonate's off-gassing during firing

It is used in glazes to produce gray (with feldspar)

Calcined Zinc Oxide is a useful high temperature flux

6 Tile Kaolin is an air floated kaolin with bright firing properties yet highly plastic

soluble in water which forms a strongly alkaline solution

Mayco CG785 Royal Fantasy Jungle Gem Glaze, 4 oz Decorating Accessories and it is caused byApply to shelf cone 04 bisque. Shake jar well and stir during the application process. Apply 3 coats with a fan brush, allow to dry between coats. Avoid placing crystals towards bottom of ware to keep them from flowing onto the kiln shelf during firing. The crystals in the glaze will melt when fired, which may create a textured surface. As that surface may be difficult to properly clean if in contact with food, we recommend crystal glazes to be used