Abstract The only deposit in the world mined solely for its lanthanide content is that of Molycorp at Mountain Pass, California, U.S.A. The current processes for producing commercial quantities from this ore will be illustrated and described. The present industrial applications in the areas of metallurgy, glass, ceramics, catalysts, and phosphors will be briefly summarized. New uses for lanthanides, as metals and as compounds, in various technologies are under development by many companies. The principles underlying the following potential uses, and others, will be considered: 1. in Glass - as a melting aid to reduce the temperature required for melt homogeneity; 2. in Metal - as dispersion strengtheners in high performance alloys; 3. in Ceramics - as sintering aids in the production of new ceramics; 4. in Catalysts - for the control of sulfur dioxide emissions.