Titanium is the ninth most abundant element, making up about 0.6% Of the earth's crust. It occurs in nature only in chemical combination, usually with oxygen and iron. The titanium industry is based on the unique properties of titanium metal and titanium dioxide. Titanium metal, because of its high strength-to-weight ratio and resistance to corrosion, is an important strategic and critical material, and is widely used for high performance military and civilian aircraft (both in airframes and engines), for powerplant surface condensors, and a wide variety of chemical processing and handling equipment. Titanium metal is produced by highly sophisticated chemical processes and is, therefore, much more expensive than aluminum or steel. Only about 5% of the world's annual production of titanium minerals goes to make titanium metal. The other 95% of titanium minerals is used primarily to make white titanium dioxide pigment. Because of its whiteness, high refractive index, and resulting light-scattering ability, titanium dioxide in its two main allotropic forms, rutile and anatase, is the predominant white pigment for paints, paper, plastics, rubber, and various other materials. This Bureau of Mines report presents comprehensive data on titanium including strategic considerations, problems, technology trends and developments, reserves-resources, supply-demand relationships, economic factors and problems, operating factors and problems, and outlook to 2000.