The paper presents the results of mineralogical and physical analyses carried out on 17 Roman ceramic fragments (bricks and tiles) from Ulpia Traiana Sarmizegetusa performed for emphasizing some physical characteristics and firing parameters. These data will provide arguments for petrographical and archaeological correlations in a subsequent publication. Macroscopically, the tegular materials shows homogeneous, brown-reddish colours but hues vary from brown-reddish to orange, grown-yellowish, brown-greyish, light grey to yellowish. In some case, the colour is heterogeneous, as a rule with different hues in the interior, as compared to the external part of the ceramic fragment. For most of the samples, the matrix is relatively homogeneous, no areas with clast aggregates being evidenced. The X-ray diffraction (XRD) patterns point to a relatively simple mineralogical composition: quartz, K- and Ca-Na-feldspars, and micas. Clay minerals could be identified only based on the 4.5 Å and 2.6 Å lines. “Accessory” minerals are represented by carbonates, hematite and tremolite. Only one sample evidenced the presence of illite–vermiculite mixed layered clays. The microscopic granulometric measurements under transmitted light allowed the definition of a single category of tegular material, i.e. coarse ceramics, of siltic-arenitic-lutitic type. Two types of fabric were identified in the ceramic matrix, based on the relative ratios between the crystalline vs. the amorphous components: microcrystalline-amorphous, and amorphous-microcrystalline to amorphous. The ceramic matrix contains lithoclasts (quartzites, gneisses, micaschists), crystalloclasts (quartz, epidote, zoisite, garnets, titanite, zircon, hornblende, micas), and ceramoclasts. The porosity varies in narrow limits and it consists of both primary pores, usually elongated and displayed parallel to the surfaces, and secondary, irregular pores. The pores sizes vary between 0.5 x 1.5 – 2.0 x 3.0 mm. Samples compaction, evaluated as water adsorption capacity shows values between 12.55 – 19.19 % for bricks, and between 14.90 – 16.98 % for tiles.

 

 

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