Yttrium occurs, in the terrestrial crust, associated to the rare earths due to its common geochemical origin. As a phosphate, yttrium occurs in the mineral xenotime and monazite, and as silicate in the gadollinite and as columbate in the samarskite. Other minerals with considerable amounts of yttrium are fergusonite, apatite, blomstrandite and euxenite. These ores are generally called yttrium earths.

The main deposits of these minerals are located in Norway, USA, Canada and Brazil. Yttrium is present in the terrestrial crust in concentrations of no more than 40 ppm.