Caracterização química, física e mineralógica da colecção de azulejos hispano-mouriscos do Museu de Lisboa - Teatro Romano

This work intends to study a set of Hispano-Moresque tile fragments from the Lisbon Roman Theatre Museum collection. The chemical and morphological characterization of the glazes and the ceramic body was presented and also the mineralogical characterization of the latter. The glazes are plumbic, being the opacity of the white and blue colors due to SnO₂ (4-11 %). The other colors present amounts of SnO₂ lower than 2 %. The ceramic body is typical of calcite-based pastes with CaO between 16-28 % and Fe₂O₃ between 4-5 %, the latter being responsible for the cream/ rose color. The mineralogical study identified wollastonite, calcite, diopside and calcic plagioclases. The results indicate that the firing temperature was generally around 1000 ºC while in some cases it was probably closer to 900 ºC. Physical characterization revealed values of 30-42 % for open porosity, a bimodal pore size distribution, a maximum water absorption of 16-26 % and a water absorption coefficient by capillarity of 1,5-6,1 kg·m^-2·h^-1/2.