Scandium Statistics and Information

Scandium, a transition metal, is the lightest rare earth element (REE), but is classified neither as a light rare earth element (LREE) nor as a heavy rare earth element (HREE). Scandium is a soft, lightweight, silvery-white metal, similar in appearance and weight to aluminum.  Although its occurrence in crustal rocks is greater than that of lead, mercury, and the precious metals, scandium rarely occurs in concentrated quantities because it does not selectively combine with the common ore-forming anions.

Excluding scandium (atomic number 21), an REE can be classified as either a light rare-earth element (LREE) or a heavy rare-earth element (HREE). The LREEs include the lanthanide elements from atomic number 57 (La) through atomic number 64 (Gd) and the HREEs include the lanthanide elements from atomic number 65 (tb) through atomic number 71 (Lu). The division is based on the LREES having unpaired electrons in the 4f electron shell and HREES having paired electrons in the 4f electron shell.

Scandium is included in the USGS Minerals Yearbook rare earths chapter, although a separate Mineral Commodity Summaries is published. These publications are available on the rare earths webpage.