# Mineral Powder Extraction by the Natural Drying of Water from the Public Springs in Borsec
## Results
### Mineral Crystallization Assessment  
The water property investigation reveals significant differences between the first and the second campaign regarding the mineral content. In consequence, the crystals' development must be followed distinctly for each campaign. The XRD pattern results for the samples crystallized from the first campaign are presented in Figure 3a and from the second campaign in Figure 3b. Significant differences are observed: the diffraction peaks observed for the first campaign are relatively weaker than those observed for the second campaign, proving that there is higher mineralization in the water samples collected in March 2024 compared to those from November 2023. Significant differences for each sample during the first campaign can be observed in Figure 3a. The XRD pattern for the S3 sample has very well-developed peaks for calcite, mainly for the (012) and (104) crystallographic planes, having strong intensities and narrow aspects; the other minerals have less intense peaks due to their particular crystal development and their number compared to the calcite grains. Thus, calcite is followed by pseudo-dolomite, aragonite, and natron. The halite peaks are very weak, being almost constrained to the XRD pattern baseline, but the presence of halite is sustained by the small amount of chloride measured in the water sample. The presence of small peaks indicates that chloride ions are combined with sodium ions generating crystalline halite. The habit of the formed crystals will be discussed at the mineralogical optical microscopy (POM) investigation. The XRD patterns obtained for the S5 and S11 samples are very similar to those for the S3 sample; only minor variation in the relative intensities is observed. The weaker peaks are developed for the S11 sample due to the relatively low mineralization, in good agreement with its water properties. Samples S6 and S11 present the most intense and narrow diffraction peaks for calcite, pseudo-dolomite, and aragonite sustaining the development of strong crystals precipitated from the water samples during the drying process. The pseudo-dolomite peak for the (104) crystallographic plane is very well developed in the S6 and S11 samples. The natron and halite peaks are less intense and slightly broadened. Thus, the dominant mineral in S6 and S11 is calcite accompanied by significant amounts of dolomite and aragonite indicating a prolific germination and crystallization from the supersaturated water solution under the drying process. The weight percent of each mineral was determined by the RIR (Reference Intensity Ratio) method [18; 19] and the values are centralized in Table 3 along with the POM results. The crystallization process was more intense in the samples collected in the second campaign, as observed in Figure 3b. Well-developed peaks with strong intensities and narrow aspects predominate. Calcite is the dominant mineral in all samples featuring very vigorous peaks for the (012) and (104) diffracting planes, but its amount strongly depends on the crystallization of the other minerals, mainly pseudo-dolomite and aragonite. The weight percentage of each mineral was determined by the RIR method and centralized in Table 3.  
The calcite amount in S3 and S5 certainly exceeds 50% of the composition while in sample S11, it overwhelms the other minerals. This indicates the strong calcium carbonaceous characteristics of these springs. The pseudo-dolomite amount is rather moderate in the range of 17-18% indicating an average magnesium level during crystallization, but its diffraction peak for (104) is well developed. The halite peaks have low intensities and slightly broadened aspects associated with a low amount and marginal crystallization beside well-developed grains. Also, natron's presence is moderate due to its relatively low peak intensities indicating the presence of tiny acicular-prismatic crystals. This fact agrees with the composition presented in Table 2 where the Na\({}^{+}\) amount is lower for S3 and S5 but average for S11.