What is "lanthanite"

Lanthanite \Lan"tha*nite\ (l[a^]n"th[.a]*n[imac]t), n. (Min.) Hydrous carbonate of lanthanum, found in tabular white crystals.

n. (context mineralogy English) A radioactive mineral, a carbonate of the rare earth elements lanthanum, cerium, and neodymium.

Lanthanites are a group of isostructural rare earth element (REE) carbonate minerals. This group comprises the minerals lanthanite-(La), lanthanite-(Ce), and lanthanite-(Nd). This mineral group has the general chemical formula of (REE)(CO)·8(HO). Lanthanites include La, Ce, and Nd as major elements and often contain subordinate amounts of other REEs including praseodymium (Pr), samarium (Sm), europium (Eu) and dysprosium (Dy). The lanthanite crystal structure consists of layers of 10-fold coordinated REE- oxygen (O) polyhedra and carbonate (CO) groups connected by hydrogen bonds to interlayer water molecules, forming a highly hydrated structure.