Petrography of mortar joint samples at different scales: (A) SEM-BSE overall view shows an angular to sub-angular aggregate into a silty–clayey matrix; (B) angular quartz and very fine grained minerals form the matrix (SEM-BSE image); (C) high magnification morphological image of the matrix. Ab = albite; Cc = calcite; Qtz = quartz; R.F. = rock fragment.
Petrography of mortar joint samples at different scales: (A) SEM-BSE overall view shows an angular to sub-angular aggregate into a silty–clayey matrix; (B) angular quartz and very fine grained minerals form the matrix (SEM-BSE image); (C) high magnification morphological image of the matrix. Ab = albite; Cc = calcite; Qtz = quartz; R.F. = rock fragment.

Earthen mortars have been widely used in low and high status architectures of Cremona (Northern Italy) since Roman times until the XIXth century. The mineralogical, petrographic and geochemical study of XVIIIth century earthen mortars from Cremona allowed to have insights on the typology of silicate raw materials utilized for their production. The occurrence of CaO-rich levels with abundant neogenic phases and widespread dissolution textures suggests that small amounts of lime and other additives were blended with the silicate mixture. The results of this work help answer archeological questions about these poorly known masonry materials and provide insights for restoration purposes.

This paper was originally published in Materials Characterization 103 (2015), Pages 81-89.

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