What mineral is in porcelain sinks?
Aluminous porcelain. Porcelain is a glass product with a
crystalline internal structure. In the case of porcelain used in
sinks and toilets, the crystalline inclusions are mostly aluminum
oxide which makes the glass tough and difficult to break. It also
makes the porcelain opaque. Aluminum oxide is also used in the
formulation of the glass matrix as a stabilizer. In this form, the
aluminum oxide does not affect the translucency of the glass, but,
rather makes it stronger and reduces the solubility of the
glass.