ceramics

Ceramic material or ceramic is an inorganic solid material, produced by high-temperature chemical reactions from silicates, aluminosilicates, oxides, nitrides, carbides, borides.[1] The general properties of ceramic materials from a chemical point of view are non-reactivity, from mechanical properties hardness, high thermal stability and fragility, and from electrical non-conductivity. Materials based on (alumino)silicates (mainly clays) such as bricks, porcelain, etc. are referred to as traditional ceramics. (some have been known since the Neolithic), other materials are called technical or engineering ceramics.

Ceramic material exceptionally contains one type of crystalline phase, as a rule it contains several ceramic phases:

remains of unreacted raw materials, 1 or more types of crystals, formed by heat reactions and often glass, formed by melting melts and other glass-forming components
the last phase is the gaseous phase, enclosed in pores.