La
Lanthanum is one of many chemical elements
that geochemists call "incompatible elements."
Others that commonly appear in reports of rock analyses
are Y, Zr, Nb, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb,
Lu, Hf, Ta, Th, and U. Incompatible elements tend to be
in higher concentrations in Earth rocks than in meteorites.
Among meteorites, only some from the Moon have concentrations
in the range of typical terrestrial igneous rocks.
See Notes,
Caveats, and References
see also "Rare Earth Elements
(REE) in Lunar Meteorites"