Lanthanite n. : Hydrous carbonate of lanthanum, found in tabular while crystals.

Example:


Taxonomy
lanthanoids, lanthanoid, elements, trivalent, Rare earth elements, lanthanum, lanthanide, minerals, atoms, 4f, abundance, metals, free encyclopedia, lutetium, geochemical, orbitals, ligand, complexes.

Defination from the web:
lanthanide) series comprises the fifteen elements with atomic numbers 57 through ... The ionic radii of the lanthanoids decrease through the period — the so-called lanthanide contraction. ...