whiteware
Whiteware is the great family of everyday fired-clay objects that come out of the kiln white or near-white: your dinner plate and coffee mug, the bathroom sink and toilet, the white insulator on a power pole, and the wall and floor tiles in a kitchen. The name simply describes the fired colour — a body made of clean, iron-poor clays that fire pale rather than the red-brown of a garden flowerpot. It is the most familiar ceramic in the world, and it is made from a recipe humans have been refining for thousands of years.
The classic whiteware body is a triaxial blend of three raw powders, each with a job. Clay (mostly the mineral kaolinite) gives plasticity, so the wet mix can be thrown, cast, or pressed into shape and hold that shape while it dries. Feldspar is the flux: on firing it melts to a glass that flows between the other particles and glues them together, letting the body densify at a reachable temperature, roughly 1200 to 1400 degrees C. Quartz (ground flint or sand) is the filler that stiffens the body during firing and controls shrinkage. A common porcelain recipe is close to 50 percent clay, 25 percent feldspar, 25 percent quartz. During firing the feldspar glass and some clay dissolve and react to grow needle-like mullite crystals, and the fired piece ends up as those mullite crystals and leftover quartz locked in a glassy matrix.
Whitewares are graded by how dense and vitrified (glassy) the fired body is, which sets how much water it soaks up. Earthenware is fired lower, stays porous, and must be glazed to hold water; stoneware is denser and stronger; porcelain and vitreous china are fired until the pores close and the body is nearly water-tight and translucent at the edges. This one family therefore covers tableware, sanitaryware (sinks and toilets), electrical porcelain insulators, and much wall and floor tile. The honest caveat is that whiteware is still a brittle ceramic: strong in compression, weak in tension, and it fails from its worst flaw — which is exactly why a dropped mug shatters at a chip or a hidden crack.
A porcelain dinner plate starts as a slip (a watery clay-feldspar-quartz slurry) poured into a plaster mould or pressed on a jigger, is dried, glazed, and fired near 1300 degrees C; the feldspar melts to glass, mullite needles grow through it, the pores close, and the plate comes out white, ringing when tapped, and dense enough to hold soup without leaking.
Clay for plasticity, feldspar to melt and bond, quartz to stiffen — the triaxial recipe behind almost all white tableware, tile, and sanitaryware.
White does not mean high-tech. Whiteware is a traditional silicate ceramic, chemically dominated by a glassy phase; do not confuse it with high-purity engineering alumina or zirconia, which are far stronger, made from single-oxide powders, and fired to almost no glass.