We report all-UV coherent anti-Stokes Raman scattering (CARS) in calcite with 250-280 nm pump, Stokes, probe, and anti-Stokes light. UV CARS efficiency is approximately 7x higher than for comparable scattering in the visible, 480-540 nm. Time-resolved UV CARS reveals lengthening of the dephasing time of 1086 cm(-1) CO3(2-) internal vibrations from 4 to 7 ps with increasing vibrational excitation, consistent with a phonon depletion model.