A shock-induced polymorph (TiO 2 II) of anatase and rutile has been identifi ed in breccias from the late Eocene Chesapeake Bay impact structure. The breccia samples are from a recent, partially cored test hole in the central uplift at Cape Charles, Virginia. The drill cores from 744 to 823 m depth consist of suevitic crystalline-clast breccia and brecciated cataclastic gneiss in which the TiO 2 phases anatase and rutile are common accessory minerals. Electron-microprobe imaging and laser Raman spectroscopy of TiO 2 crystals, and powder X-ray diffraction (XRD) of mineral concentrates, confi rm that a high-pressure, α-PbO 2 structured polymorph of TiO 2 (TiO 2 II) coexists with anatase and rutile in matrix-hosted crystals and in inclusions within chlorite. Raman spectra of this polymorph include strong bands at wavenumbers (cm -1 ) 175, 281, 315, 342, 356, 425, 531, 571, and 604; they appear with anatase bands at 397, 515, and 634 cm -1 , and rutile bands at 441 and 608 cm -1 . XRD patterns reveal 12 lines from the polymorph that do not signifi cantly interfere with those of anatase or rutile, and are consistent with the TiO 2 II that was fi rst reported to occur naturally as a shock-induced phase in rutile from the Ries crater in Germany. The recognition here of a second natural shock-induced occurrence of TiO 2 II suggests that its presence in rocks that have not been subjected to ultrahigh-pressure regional metamorphism can be a diagnostic indicator for confi rmation of suspected impact structures.