## 3 Results and Discussion
### Chemical Make-Up via X-ray Fluorescence (XRF)
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample Category** **Number(s)**} & \multirow{2}{*}{**Sample(s) Name**} & **Dolomite Pure or Dolomite (with Fe)** & **Other Major/Minor Phases** \\  & & **Concentration (as Reference Phase)** & **[wt\% of Phase\%]** \\ \hline \hline \multirow{8}{*}{1} & Commercial + Hand & & Magnesite (with Ca and Fe): 23.70 \\  & Crushed STF (N\({}_{2}\) ambient) & & Magnesite (low Ca and Fe) 2.28 \\  & [CO-Dolo-STFN2] & & Ankerite (pure): 7.56 Cr-Ni \\  & [CO-Dolo-STFN2] & & Oakrite (3.19) \\  & [CO-Dolo-STFN2] & & Calcite: 2.09 \\  & [CO-Dolo-STFN2] & & DeGrine (with Fe): 29.38 \\  & & & Quartz: 0.36 \\  & & & Amphibole: 1.46 \\  & & & Unclassified: 19.74 \\  & & & Calcite: 17.46 \\
2. & Hand Picked + Hand & Dolomite (pure): 49.60 & Quartz: 21.67 \\  & Crushed [HP-Dolo] & Dolomite (with Fe): 0.08 & Amphibole: 1.26 \\  & & & Unclassified: 6.36 \\  & & & Calcite: 0.82 \\
3 & Hand Picked + Ball Milled & Dolomite (pure): 74.90 & Quartz: 6.42 \\  & (Acetone) [HP-Dolo-BM] & Dolomite (with Fe): 0.53 & Amphibole: 1.85 \\  & & & Unclassified: 13.37 \\  & & & Ankerite: 3.71 \\
4 & Hand Picked + Crushed STF (N\({}_{2}\) ambient) & & DeGrine (pure): 0.50\% \\  & [HP-Dolo-STFN2] & & Dolomite (with Fe): 3.51 \\  & & & Unclassified: 16.92 \\  & & & Ankerite: 0.48 \\
5 & Hand Picked + Hand & Dolomite (pure): 1.15 & Quartz: 14.26 \\  & & & Unclassified: 8.01 \\  & [HP-Dolo-STFO2] & Dolomite (with Fe): 0.31 & Amphibole: 63.47 \\  & & & Unclassified: 9.33 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Semi-quantitative results of samples under automated SEM-EDX Mineralogy (FP-SEM-EDX) at Colorado School of Mines. to investigate the effect of the calcination process involving CO\({}_{2}\) decomposition. It is observed that the initial dolomite phase of 49.6% and calcite phase of 17.5% was identified in the [HP-Dolo] samples and are considered to be the major contributing phases for thermal decomposition of CO\({}_{2}\). Therefore, there is an increase of by-product Amphibole phase formation up to 52% in [HP-Dolo-STFN2] and 63% in [HP-Dolo-STFO2]. Approximately 4-8% of a minority satellite phase Anorthite was formed. There was a slight reduction of about 6% quartz phase between the handpicked dolomite sample and its calcined counterparts maybe due to inhomogeneities of the sample or measurement technique error. Moreover, the SiO\({}_{2}\) characterization is of not much interest since this phase does not contribute for any thermochemical reactions, this quartz phase is considered to a dead weight and not further explored. For samples 4 [HP-Dolo-STFN2] and 5 [HP-Dolo-STFO2], the SiO\({}_{2}\) or quartz phase was identified by the Automated SEM-EDX Mineralogy are 15.975%, and 14.26%, respectively (please see Table 2). These mass percentages in close match with our XRF results as reported in Table 1, for the sample HP-Dolo-STF, the SiO\({}_{2}\) phase is \(\sim\)24.1 wt%. With this high concentration of SiO\({}_{2}\) phase and the calcination of dolomites, the tube furnace ends up with Amphibole formation. On the other hand, for the non-calciend [HP-Dolo] sample, even though the SiO\({}_{2}\) concentration of 21.67% (sample 2 in Table 2) and 32 wt% in Table 1, there was no Amphibole formation. Yet, another closer look of calcined commercial dolomite, sample 1 [CO-Dolo-STFN2], the Amphibole formation is less than 2 wt%, due to the low concentration of SiO\({}_{2}\) (0.36%). The same is true for the handpicked and ball milled sample 3 [HP-Dolo-BM], without further calcination, the Amphibole phase is less than 2% while the SiO\({}_{2}\) is reported in Table 2, with 6.42%. Based on the above analysis, it is very clear that, for the formation Amphibole phase, a sample composition parameter with a high concentration of SiO\({}_{2}\) (\(>\)15 wt%), the sample must undergo high temperature calcination.