# Rock Emissivity Measurement for Infrared Thermography Engineering Geological Applications
## 3 Materials  
The targets of this research are 27 specimens belonging to 15 different rock types chosen among sedimentary, igneous and metamorphic categories (Figure 2). Specimens offer a planar surface, either smooth or polished, to be framed by IRT.  
The sedimentary lithologies taken into account herein include:  
* Limestones (L): fine-grained, light beige, limestone with a porous texture, showing millimetric voids and rare traces of bioturbation. This rock type was specifically employed for the reconstruction of a UNESCO world heritage monument in south-eastern Sicily.
* Calcarenites (C): two varieties of sicilian calcarenites were tested herein. The first is known as Sabucina stone, classifiable as a yellowish biosparite, with allochems mainly given by small fragments of foraminifera/bryozoa and orthochems represented by spathic calcite and small amount of micrite [39] and reference therein. The second belongs to the \"Panchina\" formation and it is a yellowish organogen calcarenite. Rocks show a porous texture, with micro and macro voids up to millimetric size.
* Quartzarenites (QA): belonging to the arenaceous member of a Flysch succession, such greyish rocks contain sharp to sub-rounded lithic fragments (<1 mm) and widely crop out in northeastern Sicily.
* Calcisiltite (CS): dark grey marly calcisiltites, with rare mineral clasts in a microcrystalline carbonate cement.
* Sandstones (S): yellowish to grayish sandstones affected by a grain-size variability, from fine-to medium belonging to the Capo d'Orlando Flysch formation of northern Sicily. Such sandstones have been defined as quartzofeldspathic arccos [40] and references therein.
* Dolostones (D): cropping out on the Peloritani Mountains (northeastern Sicily) and belonging to the Longi-Taormina Unit, these rocks are characterized by a massive to brecciated structure and show the occurrence of calcite veins. Color ranges from grey to a light pink.  
Figure 2: Some representative specimens belonging to the different rock categories tested herein.  
Travertine (T): cream-colored banded rock composed of calcite, usually formed by the evaporation of river and precipitation of carbonate minerals at spring waters. It is a variety of rock often used for walls and interior decorations. Igneous samples are: - Basalt: volcanic, effusive rocks from Mount Etna. At hand-scale, specimens show a porphyritic texture with a massive (Bm) or vesicular (Bv) structure. In the first case, olivine, pyroxene and plagioclase crystals are found in a groundmass and no visible voids can be detected; in the second case, millimetric voids occur within the rock structure, e.g., [41]. - Granite: coarse-grained igneous rock mainly composed of quartz, alkali feldspar, and plagioclase tested herein in three different varieties, i.e., alkali feldspar granite also known as \"red granite\" with both polished (AGp) and smooth (AGs) surface; K-feldspar pinkish granite with both polished (KGp) and smooth (KGs) surface; white plagioclase granite (WG) with a smooth surface. - Tuff (TF): medium grain sized volcanic grayish rock, with plagioclase, biotite, with pumice concentration. Metamorphic samples are: - Migmatites (M): massive and fracture-free rocks, with the occurrence of banding given by millimetric alternation of leucocratic and melanocratic portions. The mineral content is represented by quartz, plagioclase, biotite and muscovite with minor chlorite, K-feldspar, and sillimanite. - Serpentinites (SP): dark green rocks sometimes affected by affected by serpentine and calcite veins. - Slate (ST): black fine-grained, foliated, low-grade metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash. - Granitoid plutonites (GP): holocrystalline rocks with a faneritic texture mainly composed of quartz, plagioclase, biotite and muscovite. - Marble: white metamorphic rock composed of recrystallized carbonate minerals from a limestone or dolomite protoolith, with both polished (MBp) and smooth (MBs) surface.