  We study a class of power-law stored energy functions for spherically
symmetric elastic bodies that includes well-known material models, such as the
Saint Venant-Kirchhoff, Hadamard, Signorini and John models. We identify a
finite subclass of these stored energy functions, which we call Lam\'e type,
that depend on no more material parameters than the bulk modulus $\kappa>0$ and
the Poisson ratio $-1<\nu\leq1/2$. A general theorem proving the existence of
static self-gravitating elastic balls for some power-law materials has been
given elsewhere. In this paper numerical evidence is provided that some
hypotheses in this theorem are necessary, while others are not.
