Fire at Cone 04-06. Textural Glazes Astro Gems are non-moving textural glazes that contain tiny crystals. They are non-toxic, but not dinnerware safe. They are normally fired at Cone 019 which is much cooler than the bisque fire. Metallic Overglazes are real metals are used to produce gold, silver and related rich finishes.
Lusters give a colored, deep metallic look to fired ceramics.