We have studied quenched high pressure phases in the CaSiO3 system by x-ray diffraction (XRD) and 29Si MAS NMR. XRD study of the previously reported ''&egr;-CaSiO3 phase'' synthesized at 12 GPa and 1500 ¿C reveals that it is actually a mixture of &bgr;-Ca2SiO4 (larnite) and a previously unknown CaSi2O5 phase. This result is supported by the 29Si NMR spectra. Furthermore, both the XRD and the NMR data suggest that the CaSi2O5 phase may have a titanite (CaTiSiO5) structure in which Ti is replaced by an octahedral Si. Samples quenched from 15 GPa and 1500 ¿C consist mostly of an amorphous phase, but a small amount of CaSiO3-perovskite was identified by both XRD and NMR. The 29Si NMR spectrum of the amorphous phase suggests that its local structure is similar to that of a glass quenched from melt at 1 bar. ¿ American Geophysical Union 1991