Fig. 10: Analysis of an EB grain from the wall cross-section BR03.

a Brightfield optical micrograph of BR03, highlighting the largest blue particle, and its corresponding EDS elemental map b. c Raman map differentiating phases as EB (blue), calcite (red), quartz (green), wollastonite (orange), and fluorescence from the matrix (yellow), and their corresponding Raman spectra d.