## 3 Results and Discussion
### XRD Phase Analysis of the Obtained Products after Firing under Different Conditions
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Sample W5**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite & 72.6 \(\pm\) 5.2 & Forsterite Ferroan & 93.3 \(\pm\) 6.7 \\ Enstatite Ferroan & 27.4 \(\pm\) 3.1 & Clinoenstatite & 2.8 \(\pm\) 0.7 \\  & & Maghemite & 3.9 \(\pm\) 0.8 \\ \hline  & \multicolumn{3}{c}{**Sample W5-5\% Fe\({}_{2}\)O\({}_{3}\)**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1300 \({}^{\circ}\)C, 120 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite Ferroan & 64.3 \(\pm\) 4.6 & 63.2 \(\pm\) 4.5 & Forsterite Ferroan & 90.6 \(\pm\) 6.6 \\ Protoenstatite & 19.9 \(\pm\) 1.2 & 21.4 \(\pm\) 1.2 & Clinoenstatite & 4.8 \(\pm\) 0.6 \\ Magnesioferrite & 15.8 \(\pm\) 1.6 & 15.4 \(\pm\) 1.6 & Magnesioferrite & 4.6 \(\pm\) 0.6 \\ \hline  & \multicolumn{3}{c}{**Sample W5-10\% Fe\({}_{2}\)O\({}_{3}\)**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1300 \({}^{\circ}\)C, 120 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite Ferroan & 58.5 \(\pm\) 3.9 & 58.5 \(\pm\) 3.9 & Forsterite Ferroan & 90.0 \(\pm\) 6.3 \\ Protoenstatite & 21.1 \(\pm\) 1.9 & 21.1 \(\pm\) 1.9 & Clinoenstatite & 2.7 \(\pm\) 0.6 \\ Magnesioferrite & 20.4 \(\pm\) 1.4 & 20.4 \(\pm\) 1.4 & Magnesioferrite & 7.2 \(\pm\) 1.1 \\ \hline  & \multicolumn{3}{c}{**Sample W5 PT**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite & 73.7 \(\pm\) 5.2 & Forsterite Ferroan & 93.3 \(\pm\) 6.6 \\ Enstatite Ferroan & 23.3 \(\pm\) 2.6 & Clinoenstatite & 2.8 \(\pm\) 0.6 \\  & & Magnesioferrite & 3.9 \(\pm\) 0.6 \\ \hline  & \multicolumn{3}{c}{**Sample W5 PT-5\% Fe\({}_{2}\)O\({}_{3}\)**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1300 \({}^{\circ}\)C, 120 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite Ferroan & 69.4 \(\pm\) 4.5 & 67.8 \(\pm\) 4.3 & Forsterite Ferroan & 88.6 \(\pm\) 6.3 \\ Protoenstatite & 14.8 \(\pm\) 1.0 & 16.8 \(\pm\) 1.1 & Clinoenstatite & 5.9 \(\pm\) 0.9 \\ Magnesioferrite & 15.8 \(\pm\) 1.6 & 15.3 \(\pm\) 1.6 & Magnesioferrite & 5.5 \(\pm\) 0.9 \\ \hline  & \multicolumn{3}{c}{**Sample W5 PT-10\% Fe\({}_{2}\)O\({}_{3}\)**} \\ \hline  & **1300 \({}^{\circ}\)C, 30 min** & **1300 \({}^{\circ}\)C, 120 min** & **1600 \({}^{\circ}\)C, 60 min** \\ \hline Forsterite Ferroan & 64.1 \(\pm\) 4.6 & 64.2 \(\pm\) 4.6 & Forsterite Ferroan & 89.7 \(\pm\) 6.5 \\ Protoenstatite & 13.8 \(\pm\) 1.2 & 17.3 \(\pm\) 1.3 & Clinoenstatite & 4.5 \(\pm\) 0.8 \\ Magnesioferrite & 22.2 \(\pm\) 1.5 & 18.4 \(\pm\) 1.4 & Magnesioferrite & 5.8 \(\pm\) 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The mineralogical content (wt.%) of examined samples W5 and W5 PT with the addition of hematite and after the application of different firing conditions. (2011), the olivine particles after oxidation decompose along the particle boundary and transform to magnesioferrite crystals and pyroxene/vitreous silica, while at the same time a part of hematite can diffuse into their structure, as this presents rather high solubility in the presence of MgO (2015). At this point it must be underlined that the quantification of mineralogical phases as obtained from the XRD patterns, and the thermal treatment at 1600 \({}^{\circ}\)C refers only to the detected crystalline phases and is not representative of the overall content of the product, since there is also a high percentage of glassy phase due to the eutectic phases at the heating temperature of 1600 \({}^{\circ}\)C, which is not detected by the XRD measurements. Magnesium silicate polymorphism is observed when the samples are subjected to the thermal treatments applied in this study, and this is a matter of particular interest, as its polymorphism is a field of study that has not yet been thoroughly investigated.