  We address the fundamental difference between solid-solid and liquid-liquid
phase transitions within the Ericksen's nonlinear elasticity paradigm. To
highlight ideas, we consider the simplest nontrivial 2D problem and work with a
prototypical two-phase Hadamard material which allows one to weaken the
rigidity and explore the nature of solid-solid phase transitions in a
``near-liquid'' limit. In the language of calculus of variations we probe
limits of quasiconvexity in an ``almost liquid'' solid by comparing the
thresholds for cooperative (laminate based) and non-cooperative (inclusion
based) nucleation. Using these two types of nucleation tests we obtain for our
model material surprisingly tight two-sided bounds on the elastic binodal
without directly computing the quasiconvex envelope.
