titanium

Strong, lightweight, silver-grey, metallic element, atomic number 22, relative atomic mass 47.90. The ninth most abundant element in the Earth's crust, its compounds occur in practically all igneous rocks and their sedimentary deposits. It is very strong and resistant to corrosion, so it is used in building high-speed aircraft and spacecraft; it is also widely used in making alloys, as it unites with almost every metal except copper and aluminium. Titanium oxide is used in high-grade white pigments.

Titanium bonds with bone in a process called osseointegration. As the body does not react to the titanium it is valuable for permanent implants such as prostheses.

The element was discovered in 1791 by English mineralogist William Gregor (1761–1817) and was named by German chemist Martin Klaproth in 1796 after the Titans, the giants of Greek mythology. It was not obtained in pure form until 1925.