Titanium compounds are widely distributed in nature. Rutile, the native dioxide, and ilmenite, which contains, besides titanium, iron and oxygen, are its chief sources. The metal cannot be produced by reduction of the dioxide, because titanium reacts with both oxygen and nitrogen at high temperatures. One method used consists in passing chlorine over ilmenite or rutile, heated to redness with carbon. Titanium is present in the sun and certain other stars, in meteorites, and on the moon.
Titanium dioxide causes the star effect in certain sapphires and rubies.
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