Bastnäsite

Bastnaesite is the name for a group of minerals that belong to the carbonates and nitrates. They contain metals called rare earths, e.g. cerium, lanthanum, neodymium and yttrium. Natural deposits always contain two or more rare earths due to the formation of solid solutions. Bastnaesites are mainly used for the extraction of rare earths, only particularly clear and beautiful specimens are processed into gemstones. The name comes from an ore mine near Bastnäs in Sweden, where in 1838 a bastnaesite was found for the first time and named after its origin by a mineralogist.

Bastnaesites occur in waxy to honey yellow, brick red to crimson and reddish brown to dark brown colors. They are 4 to 4.5 on the Mohs scale. They are formed mainly by magmatic activity in carbonatites and pegmatites. They have been found in more than 400 sites. The most important of them are Mountain Pass in California, Bayan Obo in China as well as several in Madagascar. Especially beautiful and clear bastnaesites are found in France as well as in Pakistan. The crystals found at the Pakistani mountain Zagi are known for their strong red-brown coloration and their particularly even formation.