How id oxide related to ceramics?
What is oxide? How is it related to pottery? Pottery Clay will walk you though this.
Oxide is a chemical compound added to the ceramic glaze to yield different properties during the firing temperature. The results appear on the surface of the glaze and other special effects including crackle glaze or crystallization. There are many kinds of oxides including the one producing opaque glaze such as tin dioxide. (Tin), titanium dioxide (Titanium) oxide producing opaque is zirconium dioxide (Zirconuim) oxide producing crystallization is zinc oxide. (Zinc oxide) oxide producing colorant is ferric oxide.(Ferric) and cobalt oxide (Cobalt)
Amount does matter! Different amount of oxide results in different results. Large amount of zinc oxide (Zinc ) resulting in crystallization will cause defection on the glaze. Therefore, potter must carefully study appropriate amount of additives to be mixed with the glaze for the perfect results as desired.
One precaution before using oxide is that it is a fluffy powder which can be diffused in the air. Therefore, it must be stored in a secured container. Mouth and nose must be covered to protect yourself from the particle. Avoid direct contact with the chemical because it is poisonous. Gloves must always be worn before using oxide.
Moreover, what should always keep in mind is that the poisonous chemical substance that must not be added to the glaze for tableware are barium oxide, zinc oxide, lead dioxide, cadmium oxide, nickel oxide, cobalt oxide at more than 5% Most people misunderstand that once the glaze are fired and turned to crystal, it is safe to be used for tableware. Actually, even foods with minimum acid can cause chemical contamination.