Figure 2

Two Raman spectra collected in the A1 wall of the peristyle in House of Gilded Cupid (Pompeii): (a) Calcite (1086 cm⁻¹), syngenite (982 and 1006 cm⁻¹) and niter (1049 cm⁻¹) were identified as a complex mixture, (b) epsomite (985 cm⁻¹) and calcite (1085 cm⁻¹) were observed together with fluorescence signals from silicates.