Ceramic is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material. Some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, and weak in shearing and tension. They withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand very high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C (1,800 °F to 3,000 °F).
Hematite also spelled as haematite, is the mineral form of iron (III) oxide (Fe2O3). It forms a complete solid solution at temperatures above 950 °C (1,740 °F). Hematite is a mineral, colored black to steel or silver-gray, brown to reddish brown, or red. Huge deposits of hematite are found in banded iron formations. Gray hematite is typically found in places that can have still standing water or mineral hot springs. Hematite can also occur without water, however, usually as the result of volcanic activity.