Bastnäsite and the phosphate mineral monazite are the two largest sources of cerium, an important industrial metal.

[7] The two are both rare-earth fluorocarbonates, but parisite's formula of Ca(Ce, La, Nd)2(CO3)3F2 contains calcium (and a small amount of neodymium) and a different ratio of constituent ions.

[9] Ore from the Bastnäs Mine led to the discovery of several new minerals and chemical elements by Swedish scientists such as Jöns Jakob Berzelius, Wilhelm Hisinger and Carl Gustav Mosander.

Also found in carbonatites, a rare carbonate igneous intrusive rock, at the Fen Complex, Norway; Bayan Obo, Mongolia; Kangankunde, Malawi; Kizilcaoren, Turkey and the Mountain Pass rare earth mine in California, US.

Some bastnäsite has been found in the unusual granites of the Langesundsfjord area, Norway; Kola Peninsula, Russia; Mont Saint-Hilaire mines,[11] Ontario, and Thor Lake deposits, Northwest Territories, Canada.

The development of these crystal morphologies has been suggested[12] to be controlled by the level at which supersaturation is reached in the aqueous solution during the breakdown of the amorphous precursor.

At a lower temperature (e.g., 165 °C) and slow heating (100 min) the supersaturation levels are approached more slowly than required for spherulitic growth, and thus more regular triangular pyramidal shapes form.

In 1949, the huge carbonatite-hosted bastnäsite deposit was discovered at Mountain Pass, San Bernardino County, California, US.

The lanthanide composition of the ore included 0.1% europium oxide, which was needed by the color television industry, to provide the red phosphor, to maximize picture brightness.

Bayan Obo bastnäsite occurs in association with monazite (plus enough magnetite to sustain one of the largest steel mills in China), and unlike carbonatite bastnäsites, is relatively closer to monazite lanthanide compositions, with the exception of its generous 0.2% content of europium.

By contrast, in China, processing of bastnäsite, after concentration, starts with heating with sulfuric acid.