Figure 1.
Geological map and distribution of the sandstone tors of the STNR, Ciężkowice area (after Alexandrowicz, 1970; Cieszkowski et al., 1991; Leszczyński, 1981, modified). Quaternary deposits: 1, alluvial clays; 2, alluvial and diluvial loams. Paleogene flysch sequences: 3, Hieroglyphic Beds (green shales and sandstones); 4, Ciężkowice Sandstones (conglomeratic sandstones, conglomerates); 5, Variegated and Red Shales (shales), 6, Upper Istebna Shales (shales); 7, fault.
Figure 2.
The Ratusz tor (Town Hall tor) in the STNR showcasing the niche with white hydromagnesite efflorescence (A, B), and Czarownica tor (Witch tor) (C). (For location details, see Figure 1).
Figure 3.
Characteristic X-ray patterns of the spring-formed hydromagnesite-rich efflorescence from the Ratusz tor (A) and the hydromagnesite reflections used for the refining unit-cell parameters (B). Gp, gypsum; Hex, hexahydrite; Hmg, hydromagnesite; Qz, quartz.
Figure 4.
STA (DTA, TG and DTG) patterns for the spring efflorescence samples from the Ratusz tor (STNR).
Figure 5.
Temperature-dependent IC curves of the volatile decomposition products formed under heating of the spring efflorescence samples from the Ratusz tor (STNR) in air. IC curves for m/z = 18 (H2O), m/z = 44 (CO2) and m/z = 64 (SO2) are presented in relation to the TG curve.
Figure 6.
Backscattered electron (BSE) images of hydromagnesite from the Ratusz tor (STNR) efflorescence: general view showing thin, acicular crystals with lengths of several tens of micrometres and clusters of flocculent aggregates (A); Clusters of flocculent and flame-bladed crystals (B); Acicular crystals with irregular surfaces coated by flaky grains and loose flocculent aggregates (C). Representative EDS elemental composition of hydromagnesite crystals showing the presence of magnesium (Mg), carbon (C), and oxygen (O) (D).
Table 1.
Representative chemical compositions of the STNR hydromagnesite
| Analysis number | 2 | 18 | 24 | 26 | 30 | 31 | 32 | 35 | 39 | 34 | Average n = 10 | SD |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| wt% | ||||||||||||
| SO3 | 1.31 | 1.80 | 1.38 | 4.98 | 2.57 | 1.59 | 1.52 | 1.56 | 1.14 | 1.34 | 1.92 | 1.14 |
| P2O5 | 0.00 | 0.00 | 0.00 | 0.00 | 0.04 | 0.00 | 0.01 | 0.01 | 0.02 | 0.00 | 0.01 | 0.01 |
| SiO2 | 0.22 | 0.29 | 0.22 | 0.24 | 0.16 | 0.14 | 0.18 | 0.16 | 0.25 | 0.25 | 0.21 | 0.05 |
| Al2O3 | 0.13 | 0.07 | 0.00 | 0.02 | 0.00 | 0.00 | 0.00 | 0.09 | 0.08 | 0.06 | 0.05 | 0.05 |
| PbO | 0.01 | 0.00 | 0.00 | 0.03 | 0.00 | 0.00 | 0.02 | 0.04 | 0.05 | 0.00 | 0.01 | 0.02 |
| ZnO | 0.02 | 0.00 | 0.00 | 0.02 | 0.00 | 0.01 | 0.00 | 0.02 | 0.03 | 0.00 | 0.01 | 0.01 |
| SrO | 0.01 | 0.03 | 0.07 | 0.05 | 0.08 | 0.02 | 0.02 | 0.00 | 0.02 | 0.03 | 0.03 | 0.03 |
| MnO | 0.01 | 0.00 | 0.02 | 0.00 | 0.02 | 0.00 | 0.01 | 0.00 | 0.00 | 0.01 | 0.01 | 0.01 |
| FeO | 0.04 | 0.00 | 0.00 | 0.01 | 0.00 | 0.03 | 0.00 | 0.03 | 0.00 | 0.00 | 0.01 | 0.01 |
| CaO | 0.11 | 0.08 | 0.08 | 0.13 | 0.06 | 0.07 | 0.07 | 0.13 | 0.11 | 0.08 | 0.09 | 0.03 |
| BaO | 0.00 | 0.00 | 0.00 | 0.02 | 0.00 | 0.02 | 0.01 | 0.00 | 0.02 | 0.02 | 0.01 | 0.01 |
| MgO | 41.77 | 43.29 | 40.65 | 39.74 | 41.09 | 41.38 | 43.65 | 40.15 | 42.33 | 38.80 | 41.28 | 1.53 |
| Na2O | 0.00 | 0.00 | 0.05 | 0.03 | 0.05 | 0.06 | 0.07 | 0.03 | 0.01 | 0.03 | 0.03 | 0.02 |
| K2O | 0.04 | 0.06 | 0.07 | 0.07 | 0.05 | 0.04 | 0.07 | 0.01 | 0.00 | 0.01 | 0.04 | 0.03 |
| Total-1 | 43.66 | 45.61 | 42.54 | 45.33 | 44.11 | 43.36 | 45.62 | 42.25 | 44.06 | 40.62 | 43.72 | 1.61 |
| MgO | 41.77 | 43.29 | 40.65 | 39.74 | 41.09 | 41.38 | 43.65 | 40.15 | 42.33 | 38.80 | 41.28 | 1.53 |
| CO2* | 36.48 | 37.81 | 35.50 | 34.71 | 35.89 | 36.15 | 38.12 | 35.08 | 36.97 | 33.89 | 36.06 | 1.34 |
| H2O** | 21.76 | 18.90 | 23.85 | 25.55 | 23.02 | 22.47 | 18.23 | 24.77 | 20.70 | 27.31 | 22.66 | 2.86 |
| Total-2 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | |
| Apfu or mpfu [five cations basis] | ||||||||||||
| Mg2+ | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | 5.00 | |
| (CO3)2−*** | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | 4.00 | |
| OH−*** | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | 2.00 | |
| H2O**** | 4.83 | 3.89 | 5.57 | 6.20 | 5.27 | 5.08 | 3.68 | 5.91 | 4.47 | 6.88 | 5.14 | 1.01 |
| Unit-cell parameters | ||||||||||||
| a[Å] | b[Å] | c[Å] | β[°] | V[Å3] | ||||||||
| 10.050(8) | 8.921 (7) | 8.384 (6) | 114.291 (25) | 685.06 | ||||||||
Figure 7.
Unit-cell parameters of the STNR hydromagnesite compared to data in the literature: 1—Akao et al. (1974); 2—Akao and Iwai (1977); 3—https://webmineral.com/data/Hydromagnesite.shtml; 4—Kruszewski et al. (2020); 5—this paper.
Figure 8.
Typical Raman spectra of hydromagnesite from the Ratusz tor in STNR.
Figure 9.
Raman spectra of the STNR hydromagnesite in the 500–1800 cm−1 region.
Figure 10.
Raman spectra of the STNR hydromagnesite in the 3000–3600 cm−1 region.