# Mineral Powder Extraction by the Natural Drying of Water from the Public Springs in Borsec
## Results
### Mineral Crystallization Assessment
The second campaign's samples have a similar crystallization behavior to the previously observed samples but with more mineral abundance, as seen in Figure 5. The initial stage reveals a significant number of germination centers within S3, S5, and S11 followed by the growth of relatively small and well-formed individual crystals, shown in Figure 5(a1,b1,e1). The samples S6 and S10 having the strongest mineralization generate numerous crystallization centers that rapidly grow into relatively bigger individual crystals, as observed in Figure 5(c1,d1). The final stage of crystallization generates more developed dendrites regarding the crust density and embedded crystals for S3, S5, and S11 than those observed for the first campaign. The dendritic crust evidences the presence of halite as the embedding material towards the dendrites' borders, as observed in Figure 5(a2,b2,e2). The carbon bullets might influence the elemental analysis on the large areas by quantifying the uncovered spots explaining some abnormally increased values of carbon over the normal stoichiometric composition related to the alkaline elements. Thus, the elemental composition was determined on the large areas observed at low magnifications: 200\(\times\)-500\(\times\), shown in Figure 6.  
The broken dendrites within the S3 sample are situated in the central side of the electron image in Figure 6a and are surrounded by smaller fractions including individual crystals. The corresponding elemental map features an intense green color for the calcite and aragonite particles (due to the overlapping colors of yellow for C, turquoise for O, and green for Ca). Magnesium is labeled pink, and its distribution is observed inside of some crystalline crusts' clusters showing the refined distribution of the dolomite crystals. Chloride is labeled dark blue showing its distribution along with the halite components of the crystalline crust. We noticed that the S atoms are predominantly situated around the pseudo-dolomite crystals rather than on the calcite ones (the association between pink and orange spots in the elemental map in Figure 6a). Their occurrence is involved with some sulfur traces in the S3 water below the detection limit in Table 2. The water evaporation concentrates these traces so that they become detectable beside the pseudo-dolomite crystals. The powder resulting from the S5 broken dendrites is more refined and uniform, as observed in Figure 6b, indicating the advanced fragmentation of the formed dendrites. It is difficult to observe the individual crystals due to the low magnification. The element distribution map within Figure 6b clearly evidences pseudo-dolomite clusters having a pink color surrounded by a dense green mass of calcite and aragonite crystals. The halite fractions appear to be very fragmented; this fact is sustained by the randomly spread dark blue spots. This is a normal situation because of the lower amount of chloride ions detected in the EDX spectrum; see Table 4. The lower right corner of the element distribution map reveals a dark brown area indicating an abnormally higher carbon amount. This area is not fully covered with powder, making visible the carbon bullet, explaining the carbon excess found in the elemental composition. The S6 powder is finer than the previous one; the microstructural ensemble observed in Figure 6c reveals a compact layer of fine particles. The elemental map evidences bigger clusters containing pseudo-dolomite crystals having a pinkish nuance randomly spread in the calcite particles' mass. The halite component of the broken crystalline crust appears dark violet according to its specific label.