Bastionide

Bastionide is a rare and distinctive mineral species, first discovered in the Bastnäs mine in Sweden. It is a complex oxide mineral, with the chemical formula (Ce,La)CO3F. The mineral is named after the Bastnäs mine, where it was found, and the suffix "-ide" indicating it is a compound of cerium and lanthanum with carbon, oxygen, and fluorine.

Bastionide crystallizes in the trigonal system, forming prismatic crystals that are typically colorless or white, but can also be pink, yellow, or brown due to impurities. It has a Mohs hardness of 4.5 and a specific gravity of approximately 4.5. The mineral is often found in association with other rare earth minerals such as bastnäsite and parisite.

Bastionide is of significant interest to the mining and materials science communities due to its content of rare earth elements, which are crucial in the production of various high-tech devices and materials. The mineral's rarity and the challenges associated with its extraction make it a valuable resource in the global market for rare earth elements.