Explanatory notes
… (including parian) and bone china. All these ceramics are almost completely vitrified, hard, and are essentially … fused together. Soft porcelain contains less alumina but more silica and fluxes (e.g., feldspar). Bone china, which … impregnated with tar, or glazed, etc. They may also have moulded, embossed or indented designs on one or two faces. …