  We present a detailed analysis of spectra and other observables for the
entire chain of Zr isotopes, from neutron number 52 to 70, in the framework of
the interacting boson model with configuration mixing. The results suggest a
remarkable interplay of multiple quantum phase transitions (QPTs). One type of
QPT involves an abrupt crossing of normal and intruder configurations,
superimposed on a second type of QPT involving gradual shape-changes within
each configuration.
