Fig. 3

Energy-dispersive X-ray diffraction patterns of CaCO₃ at high pressure and high temperature. The data were collected at a fixed 2θ of 15° and the energy (E) in the x axis was transferred to d-value by the equation of \(Ed\;{\mathrm{sin}}\left( \theta \right) = 6.199\;{\mathrm{keV}} \cdot\)Å. The short red bars denote the peaks of aragonite