Yttrium geochemistry

Lawrence, M.G., Jupiter, S.D., Kamber, B. S. 2006. Aquatic geochemistry of the rare earth elements and yttrium in the Pioneer River catchment, Australia. Marine and Freshwater Research, 57, 725-736. 

They have very close chemical properties with scandium and yttrium and the whole series is often referred as rare earth elements, since lanthanides were historically isolated from uncommon oxide-type minerals. However this term is not totally adequate, the lanthanides are not to be considered as rare, because even a scarce 4f-element such as lutetium is more abundant than silver (see Geology, Geochemistry, and Natural Abundances of the Rare Earth Elements). 

The rare earth phosphates are important in the geochemistry of the rare earths, since two of the main rare earth minerals are binary orthophosphates. The most abundant of these, monazite, has the approximate composition (Ce, La)P04, while xenotime is primarily an yttrium phosphate. Several other rare earth minerals containing phosphate have been found in the earth (Gmelin, 1984). In addition, the important phosphorus sources apatite and phosphorite contain up to 1% of rare earths. 

GEOCHEMISTRY AND MINERALOGY OF THE RARE EARTHS 2. Formation and abundances of the lanthanides and yttrium... 

Wood, S.A. (1990a) The aqueous geochemistry of the rare-earth elements and yttrium. 1. Review of available low-temperature data for inorganic complexes and the inorganic REE speciation of natural waters. Chem. Geol., 82, 159-186. 

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