Stoneware is a piece with (or without) enamel, mostly composed of materials with 1200 to 1300 degree C of heat. Stoneware are utterly opaque, but have a highest strength in French, it is called "Gres", in German "Steinzeng" and in Persian "Chini-Sangi".
Species of Stoneware:
1- Natural Stoneware, produced from a kind of clay with maximum un-purity.
2- Fine Stoneware, produced of full adhesive and little adhesive clays.
3- Technical and non-porous Stoneware, produced from raw materials under control, mixed carefully and heated, with minimum porosity; these are used in most chemical industries.
4- Jasper Stoneware, in which combinations of Barium are used in abundance.
5- Bazaltic Stoneware, in which a lot of Iron-Oxide is used in the body.