Figure 2.

Raman spectra in the range 100–900 cm⁻¹ determined with the OMARS 89 System. (a) Synthetic coesite. (b) Small triangular coesite inclusion in diamond (compare with Fig. 1). The pressure was determined from the shift of the 521-cm⁻¹ peak according to ν = 520.6 + 2.9(1) *P (GPa) (27).