Infrared and Raman spectra of CO˭3ions are different in the two crystallographic forms of CaCO3Calcite and Aragonite owing to their different site symmetries. Due to this fact, i.r. has been used to assess the reversible Calcite ← → Aragonite transformation which occurs upon grinding of CaCO3, and much work has been done in this field in the last few years(1-4). In the present paper data are reported on Raman spectra of Calcite and Aragonite forms of CaCO3produced by the above mechanical procedure.