This element is dark in color, is soluble in hydrochloric and sulfuric acids and is slightly soluble in nitric acid.
Thorium occurs in thorite, in orangite and in thorianite.
The larger deposits occur as thorium oxide and are found in the monazite sands of India and Brazil. The main use of thorium has been in the preparation of the Welsbach mantle used for portable gas lights. These mantles glow with a dazzling light when heated in a gas flame. Thorium is a source of nuclear power. More energy is available for use from thorium in the minerals of the earth's crust that from both uranium and fossil fuels.