bastnäsiitti

Bastnäsiitti is a group of minerals that are important sources of rare earth elements. The general chemical formula for bastnäsiitti is (REE)CO3F, where REE represents a mixture of rare earth elements, most commonly cerium, lanthanum, neodymium, and praseodymium. These minerals typically occur in igneous rocks, particularly carbonatites and alkaline intrusive rocks. They can also be found in certain metamorphic rocks and hydrothermal deposits.

Bastnäsiitti is characterized by its light to dark brown or reddish-brown color, although it can also be yellowish or grayish. It often exhibits a vitreous to greasy luster and a hardness of around 4.5 on the Mohs scale. The crystal system of bastnäsiitti is hexagonal. It is typically found as disseminated grains, prismatic crystals, or massive aggregates.

The mineral was first described in 1839 from a discovery in Bastnäs, Sweden, which gives it its name. The primary economic significance of bastnäsiitti lies in its high concentration of rare earth elements. These elements are crucial for a wide range of modern technologies, including magnets, catalysts, and electronics. Major bastnäsiitti deposits are found in countries such as China, the United States, and Myanmar. Mining and processing of bastnäsiitti are complex due to the intricate separation required to isolate individual rare earth elements.