Plant extracts

A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous. As most common ceramics are crystalline, the definition of ceramic is often restricted to inorganic crystalline materials, as opposed to the non-crystalline glasses. The earliest ceramics were pottery objects made from clay, either by itself or mixed with other materials. Ceramics now includes domestic, industrial and building products and art objects. In the 20th century new ceramic materials were developed for use in advanced ceramic engineering, for example, in semiconductors.