Titanium is an element occurring as a bright, lustrous, brittle metal or a dark gray powder. It is the ninth most common element in Earth's crust and is found widely in igneous rocks (molten rock that becomes solid). Titanium has also been found in meteorites, in moon rocks, and in the Sun and other stars.
The first mention of titanium appears in the writings of an English clergyman and amateur scientist, William Gregor (1761-1817). In 1791, Gregor described his analysis of a mineral found in a valley in Cornwall. He reported that the mineral contained a "reddish brown calx" that he could not identify and that he thought might include "a new metallic substance." Gregor's report was printed in a European journal. It was largely ignored and his discovery was forgotten until 1795, when German chemist Martin Heinrich Klaproth (1743-1817) decided to restudy it.
Klaproth concluded that Gregor had indeed found a new element and suggested the name titanium after the Titans, the first sons of Earth according to Greek mythology.
The most important use of titanium is in alloys (metal mixtures). Titanium alloys are very strong considering their weight and can withstand great changes in temperature. These properties make them valuable in the manufacture of parts for airplanes and spacecraft.
Titanium's resistance to salt water has made it useful in alloys used in propeller blades and ship parts. The same property suggests a possible use in desalinizing systems, which remove salts from water.
Titanium dioxide, TiO2, is the most widely used compound of the element. Since TiO2 is nontoxic, it has become the most popular pigment in white paint since the use of lead compounds in paints was discontinued. Titanium dioxide is also used as a coloring in foods, ceramics, plastics, inks, and enamels, and as a filler and coater in paper. Titanium tetrachloride liquid reacts with ammonia to produce large volumes of smoke, and is used in skywriting.