History

• first discovered by amateur scientist William Gregor in black sparkly sand in 1791 (Cornwall, UK), initially named manaccanite
• German chemist Martin Klaproth rediscovered in 1795 and named it with titanium
• "It was later determined that menachanite and titanium were the same element"
• the pure metal (99.9%) was not isolated until 1910 by Matthew Hunter by heating TiCl4 with sodium in a steel bomb.

Properties

• High reactivity: forms a passive oxide layer TiO2 that protects it from corrosion. Best known for its corrosion resistance.
• Abundance: the ninth most abundant in the crust of the Earth.
• resistance to salt water (ideal for marine applications).
• the only element that burns in nitrogen (forms titanium nitride, TiN).
• Titanium is as strong as steel, but 45% lighter. It is 60% heavier than aluminum, but twice as strong.

Titanium is present in meteorites and in the sun.

Anodization

• TiO2: has an extremely high index of refraction with an optical dispersion higher than diamond; Star sapphires and rubies exhibit their asterism as a result of the presence of TiO2