## 5 Results and Discussion
### Archaeometric and Diagnostic Analysis
IV group  
The fourth group includes only the TTNi1 sample, as a replacement black mosaic's _tessera_. It is a calcarenite and it can be classified such as wackestone, according to [PERSON] (1962) [39] and biomicrite, according to [PERSON] (1959) [38]. The allochemical component consists mainly of planktonic microforaminifera (i.e., globigerinae and globotruncanae). Recrystallization phenomena of secondary calcite occur in bioclasts; also, both primary and secondary porosity (not exceeding 3%) is visible. Additionally, a thin superficial patina was detected (up to 100 \(\upmu\)m). V group  
The fifth group includes a replacement grey mosaic's _tessera_, initialled as TTGi1. From observation under the optical microscope, this fragment consists of two portions of material with distinct fabrics and compositions (Figure 4). The portion with greater thickness can be classified as wackestone, according to [PERSON] (1962) [39], where the main allochemical component is made up of planktonic microforaminifera and other bioclasts (biomicrite, according to [PERSON] (1959) [38]. Dissolution phenomena and recrystallization of secondary calcite occur within some microfossils and microfractures. Overall, the sample shows a porosity not exceeding 3%. Additionally, samples show thin superficial layers with thicknesses of up to 100 \(\upmu\)m. The less thick portion was a bedding mortar characterized by a slightly altered calcite binder, from crypto to microcrystalline. As for the aggregate fraction, quartz, plagioclase and muscovite crystals, with sub-angular to sub-rounded shapes, were recognized. A fragment of subangular cocciopesto with a diameter of about 1 mm is also observed. Finally, both primary and secondary porosity mainly due to the binder alteration is visible. **VI group**  
The sixth group includes original pinkish mosaic's _tesserae_, initialled as TTR1 and TTR2. Both _tesserae_ show a superficial alteration layer with thickness up to 500 \(\upmu\)m. In detail, TTR1 can be classified as Pelsparite, according to [PERSON] (1959) [38], or packstone, according to [PERSON] (1962) [39]. It is rather compact, slightly altered, with primary and secondary porosity less than 3%. On the contrary, the TTR2 sample, which is slightly altered, can be classified as packstone, according to [PERSON] (1962) [39], or intrasparite according to [PERSON] (1959) [38]. Quartz crystals were recognized along with dissolution phenomena and recrystallization of secondary calcite. Additionally, both _tesserae_ show superficial layers with thicknesses of up to 500 \(\upmu\)m.  
**VII group**  
The seventh group includes only a replacement pinkish mosaic's _tesserae_, initialled as TTRi1. The specimen is a calcarenite, classifiable as biomicrite, according to [PERSON] (1959) [38], or mudstone, according to [PERSON] (1962) [39]. The allochemical component is mainly made up of 15-20% of bioclasts (e.g., benthic foraminifers). The sample appears compact, with both primary and secondary porosity less than 3%. A superficial patina with a thickness of up to 350 \(\upmu\)m is also present. **VIII group**  
The eighth group includes the TLM1 and TLM2 samples belonging to floor slabs. They are veined calcitic white marbles, characterized by a medium grain size (1-3 mm) and a heteroblastic texture. No shape preferred orientation (SPO) was observed, and crystals show curved and straight grain boundaries (GBS), occasionally dentate. A total of 120\({}^{\circ}\) triple junctions and traces of cleavage were also detected [40]. Accessory minerals such as quartz, in tiny crystals, were also recognized. No alteration forms were recognized. **IX group**  
The ninth group includes eight brick samples taken from masonry structures (i.e., TL1, TL2, TL3, TL4, TL5, TL6 and TL8). The observations were performed following the descriptive scheme proposed by [PERSON] [41].