What are Rare Earths?
Rare earths ("REE") actually comprise 17 chemical elements, all belonging to the third group in the periodic table of elements.
REE are conventionally sub-divided into two categories, these being:
- Light rare earth elements ("LREE"), comprising Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm); and
- Heavy rare earth elements ("HREE"), comprising Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Luttetium (Lu)and Yttrium (Y)
Rare earth elements do not occur naturally as metallic elements, they occur in a range of minerals that includes oxides, carbonates, phosphates and halides. A total of approximately 200 REE minerals have been identified.