Fluocerite, also known as tysonite, is a mineral consisting of cerium and lanthanum fluorides, with the chemical formula (Ce,La)F3.
[1][2] The end members are classified as two different mineral types depending on the cation, fluocerite-(Ce) and fluocerite-(La), corresponding respectively to lanthanum trifluoride and cerium trifluoride.
[4] Fluocerite-(La) was first described in 1969 from the type locality in central Kazakhstan.
[3] The name tysonite was given in 1880 to the same type of mineral found in Colorado.
[7] This article about a specific halide mineral is a stub.