Bone china is a durable and translucent china that contains some calf bone to help the mixture set. Opalware is a pale white ceramic that is also known as porcelain. opal ware is also called opal glassware because it is actually hard translucent glass whereas porcelain is breakable.
Opals are formed when silica (SiO2) spheres all of a similar size, are arranged into a cubic close packed structure. This structure has the ability to diffract certain wavelengths of light based on the spacing in between layers of silica and the size of the spheres that make up the FCC lattice too. This is the basis for photonic crystals that can be created synthetically today.