Dynamic compression wave studies have been conducted on three calcite rocks. Solenhofen limestone, Oakhall limestone, and Vermont marble, in the stress range of 0-5 GPa. Plate impact techniques provided transient stress wave imput, and diffuse laser interferometry was used to study the evolution of these pulses through various thickness of rock. Both loading response and release wave response were determined from the time-resolved particle velocity profiles. The calcite I-II and II-III phase transitions dramatically influence wave propagation in this stress region. The I-II transition begins between 0.6 and 1.2 GPa depending on rock type and is found to be consistent with a reversible, diplacive polymorphic phase change. A constitutive model based on stress heterogeneity describes most of the features associated with the I-II transition. The calcite II-III transition proceeds above 2.4 GPa, and peak stress values traverse a metastable Hugoniot. This wave feature and others are more characteristic of a slower, reconstructive phase change. We conclude that stress wave features reveal striking differences in the nature of the shock-induced calcite transitions and that these transitons strongly influence the dynamic constitutive behavior of calcite rock.