The rare earths as a group constitute about 0.008% of the Earth's crust and europium generally comprises from 0.05 to 0.2% of the rare earth mixture. The principal commercial ores from which rare earths are extracted are monazite and xenotime, each being rare earth phosphates, and bastnasite, a rare earth fluocarbonate.

Monazite, a rare earth-thorium orthophosphate is found in many countries such as India, Brazil, Australia, South Africa and the United States, occurring as placer deposits on the beaches as the result of weathering and gravity concentration. It can be obtained as a by product from ilmenite, rutile, zircon and staurolite.

Bastnasite is a rare earth fluocarbonate, the largest deposit being located in the Mountain Pass region of California.