## 4 Results
### Whole Rock Chemical Analysis  
The whole rock chemical composition determined through XRF analysis (Table 2) is essential in terms of its complete characterization including economic significance [45]. The geochemical composition of the marbles, particularly their CaO/MgO ratio, may be used to classify these rocks into two major categories, irrespective of their degree of metamorphism or metasomatism [47]. As a result, Gahirat Marble is classified as calico-carbonate as a  
Figure 4: (**a**) Presence of ore minerals (Fe-oxides) with large number of calcite grains GMC1, (**b**) the calcite grain showing twin lamellae GMG1 showing minor fractures in calcite crystal. (**c**) Presence of mica (muscovite, phlogopite, and chlorite) among the calcite grains GMGG1, (**d**) the calcite grain showing invisible twin lamellae GMG21, (**e**) presence of opaque minerals (Fe-oxides) as a minor mineral with large number of calcite grains showing homoplastic texture GMD1, (**f**) the boundary of calcite grains strongly sutured and an individual calcite grain slightly recrystallized with quartz grain GMA1. calcitic marble. As observed from the ternary discrimination plot of Figure 5, the Gahirat Marble is considered Fe-poor, with calcicocarbonates displaying higher CaO and higher loss on ignition (LOI) contents compared to the magnesium carbonates (Table 2). Figure 5 shows that the calcite Gahirat Marble samples have a very low concentration of SiO\({}_{2}\), independent of their CaO/LOI ratios, which are relatively constant. [PERSON] and [PERSON] [49] used the CaO-MgOSiO\({}_{2}\) ternary diagram for the classification of marble and grouped it into 12 divisions (Figure 6). Accordingly, all the studied samples are plotted in the field of pure calcite marble. These results demonstrate that all samples of Gahirat Marble are pure calcite marble. Table 2 presents the weight percentages of the major element oxides as attained from the XRF analysis of the Gahirat Marble. The XRF study showed that all the representative marble samples exhibited high amounts of CaO and LOI due to calcite decomposition above 800 \({}^{\circ}\)C. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline
**Oxide** & **GMC** & **GMGL** & **GMKB** & **GMK** & **GMB** & **GMG** & **GMGT** & **GMGG** & **GMGZ** \\ \hline SiO\({}_{2}\) & 1.32 & 1.30 & 1.14 & 1.15 & 1.03 & 1.09 & 1.21 & 2.16 & 1.18 \\ TiO\({}_{2}\) & - & 0.05 & - & 0.04 & - & - & - & - & 0.09 \\ Al\({}_{2}\)O\({}_{3}\) & 0.50 & 0.89 & 0.74 & 0.69 & 0.61 & 0.48 & 0.58 & 0.67 & \\ MnO & - & 0.09 & - & 0.10 & - & - & 0.07 & 0.05 & - \\ CaO & 54.39 & 53.44 & 54.08 & 52.46 & 54.17 & 51.53 & 54.09 & 53.16 & 55.02 \\ MgO & 0.29 & 1.03 & 0.16 & 1.69 & 0.21 & 1.98 & 0.51 & 1.78 & 2.11 \\ Fe\({}_{2}\)O\({}_{3}\) & 0.80 & 1.95 & 1.45 & 1.78 & 1.53 & 1.23 & 1.51 & 1.49 & 1.26 \\ FeO & 0.20 & 0.54 & 0.18 & 0.15 & 0.05 & - & 0.08 & 0.20 & 0.04 \\ Na\({}_{2}\)O & - & 0.04 & - & 0.03 & - & - & - & 0.08 & 0.02 \\ K\({}_{2}\)O & 0.30 & 0.56 & 0.45 & 0.28 & - & 0.19 & 0.23 & 0.27 & - \\ P\({}_{2}\)O\({}_{5}\) & - & 0.01 & - & 0.03 & - & - & 0.02 & 0.04 & - \\ LOI & 41.10 & 39.8 & 40.7 & 40.9 & 41.1 & 41.8 & 41.1 & 39.7 & 39.26 \\ Total & 98.6 & 99.7 & 98.9 & 99.3 & 98.7 & 98.3 & 99.4 & 99.6 & 98.98 \\ \hline \end{tabular}
\end{table} 
Table 2: The whole rock geochemical analysis of the Gahirat Marble in weight % through XRF. Figure 5: Ternary CaO–20*SiO\({}_{2}\)–LOI diagram depicting the relationship between the SiO\({}_{2}\) content and the CaO/LOI ratio (**Left**). Ternary discrimination diagram of carbonated samples in the fields of calcicocarbonate, ferrocarbonate and magnesiocarbonate (**Right**) (after Woolley and Church [48]). The \"major\" oxides, SiO\({}_{2}\), Al\({}_{2}\)O\({}_{3}\), Fe\({}_{2}\)O\({}_{3}\), MgO, and K\({}_{2}\)O, exhibit very low values in the studied marble samples. The results of CaO are 96.59%, 96.59%, 95.88%, 94.06%, 96.57%, 95.03%, 95.79%, 93.17%, 95.30%, 94.97%, and 94.74 wt %, respectively.