Spectroscopic characterization of limestone and dolostone by Raman, FTIR, XRD and XRF Analyses

Building stones are durable materials, highly resistant to weathering conditions, and offer effective thermal insulation, particularly in architectural monuments and paving. The present work is a preliminary study that focuses on the characterization of two naturally occurring ornamental stones that share the same color, which is white. The first one is sourced from the Ifrane region, Morocco, and the second one is from Lisbon, Portugal. For this purpose, Raman and Fourier transform infrared spectroscopy have been used to investigate their spectral characteristics, while X-ray diffraction and X-ray fluorescence have been used to determine their crystalline phases and elemental compositions, respectively. As a result, the correlation of these techniques has revealed two types of stone: dolostone and limestone. Dolomite (CaMg(CO3)2) is the main phase in the Ifrane region stone, while calcite (CaCO3) is the main phase in Lisbon, Portugal. Furthermore, a minor amount of quartz (SiO2) was detected in both samples, which contributes to their good mechanical properties. Consequently, as for Lisbon stone, which is already used in pavement, also the stone sourced from Ifrane with its properties makes it a good choice for pavement in Morocco.