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Article

Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin

by
Andrey A. Zolotarev, Jr.
1,*,
Elena S. Zhitova
1,2,
Maria G. Krzhizhanovskaya
1,
Mikhail A. Rassomakhin
3,
Vladimir V. Shilovskikh
4 and
Sergey V. Krivovichev
1,5
1
Department of Crystallography, Institute of Earth Sciences, St. Petersburg State University, University Emb. 7/9, 199034 Saint-Petersburg, Russia
2
Institute of Volcanology and Seismology FEB RAS, Piip Blvd 9, 683006 Petropavlovsk-Kamchatsky, Russia
3
South Urals Federal Research Center of Mineralogy and Geoecology of UB RAS, 456317 Miass, Russia
4
Geomodel Research Centre, St. Petersburg State University, University Emb. 7/9, 199034 Saint-Petersburg, Russia
5
Federal Research Center, Kola Science Center, RAS, Fersmana Str. 14, 184209 Apatity, Russia
*
Author to whom correspondence should be addressed.
Minerals 2019, 9(8), 486; https://doi.org/10.3390/min9080486
Submission received: 30 July 2019 / Revised: 10 August 2019 / Accepted: 12 August 2019 / Published: 14 August 2019
(This article belongs to the Special Issue Selected Papers from the XIX International Meeting on Crystal Chemistry, X-ray Diffraction and Spectroscopy of Minerals)
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Abstract

:
The technogenic mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the burned dumps of the Chelyabinsk coal basin have been investigated by single-crystal X-ray diffraction, scanning electron microscopy and high-temperature powder X-ray diffraction. The NH4MgCl3·6H2O phase is monoclinic, space group C2/c, unit cell parameters a = 9.3091(9), b = 9.5353(7), c = 13.2941(12) Å, β = 90.089(8)° and V = 1180.05(18) Å3. The crystal structure of NH4MgCl3·6H2O was refined to R1 = 0.078 (wR2 = 0.185) on the basis of 1678 unique reflections. The (NH4)2Fe3+Cl5·H2O phase is orthorhombic, space group Pnma, unit cell parameters a = 13.725(2), b = 9.9365(16), c = 7.0370(11) Å and V = 959.7(3) Å3. The crystal structure of (NH4)2Fe3+Cl5·H2O was refined to R1 = 0.023 (wR2 = 0.066) on the basis of 2256 unique reflections. NH4MgCl3·6H2O is stable up to 90 °C and then transforms to the less hydrated phase isotypic to β-Rb(MnCl3)(H2O)2 (i.e., NH4MgCl3·2H2O), the latter phase being stable up to 150 °C. (NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. Hydrogen bonds provide an important linkage between the main structural units and play the key role in determining structural stability and physical properties of the studied phases. The mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O are isostructural with natural minerals novograblenovite and kremersite, respectively.

1. Introduction

The present publication is devoted to the detailed crystal chemical study of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O, two ammonium phases from the burned dumps of the Chelyabinsk coal basin (Chelyabinsk Oblast, Russia). Nowadays the phases from that mine are considered as anthropogenic, despite the fact that eight phases from the same locality have previously been accepted as mineral species: bazhenovite [1], godovikovite [2], dmisteinbergite [3], svyatoslavite [4], rorisite [5], efremovite [6], srebrodolskite [7] and fluorellestadite [8]. It is worthy to note that many phases first described from the burned dumps of the Chelyabinsk coal basin by Chesnokov and co-authors [9] were later found in natural environments (e.g., novograblenovite [10], pyracmonite [11], kumtyubeite [12], harmunite [13], ghiaraite [14], steklite [15], khesinite [16], rusinovite [17], etc.).
The mineral phase with the chemical composition NH4MgCl3·6H2O was first described from the Chelyabinsk coal basin as an ammonium analogue of carnallite, KMgCl3·6H2O [18], and named as “redikortsevite” [19], but this naming as well as the mineral species have not been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (CNMNC IMA). Later, this phase was found in Germany [20] and Poland [21]. Very recently, the same phase was found in a natural environment forming on the surface of basalts of the 2012–2013 Tolbachik effusive eruption (Plosky Tolbachik volcano, Kamchatka area, Far-Eastern Region, Russia) and approved by the CNMNC IMA as a mineral species named novograblenovite (NH4,K)MgCl3·6H2O [10]. Another phase studied here is the technogenic analogue of the rare mineral kremersite, (NH4,K)2[Fe3+Cl5(H2O)], that was originally described from Mt. Vesuvius (Somma-Vesuvius Complex, Naples, Campania, Italy) [22]. The pure ammonium phase, (NH4)2Fe3+Cl5·H2O, from the burned dumps of Kopeisk (Chelyabinsk coal basin) was proposed by Chesnokov [9] as a separate mineral species, the ammonium analogue of erythrosiderite, K2Fe3+Cl5·H2O [23], and named “kopeiskite”. However, this proposal was not approved by the CNMNC MMA as a species identical to kremersite. The synthetic analogue of kremersite has been suggested recently as a new multiferroic material with a strong magnetoelectric coupling [24,25].
In general, about 80 NH4-bearing minerals are known to date, with many of them being discovered recently (Table 1).
These minerals originate either as fumarolic or mofettic (i.e., ”volcanic” minerals) [10,26,30,41] or as secondary phases formed due to the contact with organic matter including burning of coal seams and dumps as well as in guano deposits (Table 1). The burned dumps of the Chelyabinsk coal basin appeared to be an important locality of ammonium compounds: at least 16 minerals and technogenic mineral-like phases were described there (Table 2). The genesis of mineral-like phases at burning coal dumps is closely related to the fumarolic formation, because both processes occur at elevated temperatures and require the principal role of gases as mineral-forming media. In principle, ammonium compounds are typical for burned coal dumps and they can form mostly during the “pseudofumarolic” stage and as a result of supergene processes [42]. The appearance of ammonium phases on burned coal dumps can be a useful indicator of the presence of underground fires [42]. At the same time, it should be noted that the origin of ferrierite-NH4 [37], which is wide spread over a large area, is not connected with underground fires.
The high-temperature study of such exhalative minerals is of interest for establishing relations between species formed at the same geochemical environment, but under different temperature regimes. Such studies have been recently performed for fumarolic minerals: saranchinaite, Na2Cu(SO4)2, and euchlorine, KNaCu3O(SO4)3, from the Tolbachik volcano (Kamchatka, Russia) [43,44] and the efflorescence mineral tschermigite, (NH4)Al(SO4)2·12H2O, from geothermal fields of Southern Kamchatka (Russia) [45]. The aim of the present study is to provide the first crystal chemical description of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O phases from the Chelyabinsk coal basin, including their first structure refinements and determinations of their stability at increasing temperatures coupled with the calculation of thermal expansion coefficients and their crystal chemical analysis.

2. Materials and Methods

2.1. Occurrence

The samples of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O phases investigated in this study were taken from the personal collection of B.V. Chesnokov currently deposited in the Natural Science Museum of the Ilmen State Reserve (Miass, Russia). Initially these samples were discovered from the coal dumps of mine No. 50 near Kopeisk city, Chelyabinsk area, Southern Urals, Russia [9]. Both phases were found in the chloride-rich crusts formed in the upper parts of the heaps of mines. “Redikortsevite”, NH4MgCl3·6H2O, crystallizes as colourless or light-yellow crystals with a flat prismatic shape. The crystals of “redikortsevite” are associated with “kopeiskite”, (NH4)2Fe3+Cl5·H2O, that forms prismatic and pseudo-octahedral crystals with a bright orange colour [9]. Both phases are very hygroscopic, easily dissolve in water and should be stored under favourable environmental conditions only, which hinders their investigation under usual atmospheric conditions.

2.2. Chemical Composition

Four crystals of “redikortsevite”, NH4MgCl3·6H2O, and “kopeiskite”, (NH4)2Fe3+Cl5·H2O, were mounted in epoxy blocks and polished. The polishing process was started on dry sandpaper and was completed on paper medium with 1 μm diamond suspension oil. The samples avoided water at all stages of polishing. The samples were coated with a 10 nm conductive carbon layer for the scanning electron microscopy (SEM) studies. Quantitative elemental analyses were carried out using a scanning electron microscope Hitachi S3400N equipped with the Oxford X-Max 20 energy-dispersive spectrometer at the Resource Centre “Geomodel” of St. Petersburg State University. The working conditions were 20 kV accelerating voltage and 1.5 nA beam current. The spectra were obtained at the spot mode for 30 s each and revealed that NH4MgCl3·6H2O contains abundant Mg, Cl, O and N, whereas (NH4)2Fe3+Cl5·H2O contains abundant Fe, Cl, O and N (Table 3). No significant zoning of crystals was observed.

2.3. Single-Crystal XRD

Single-crystal X-ray diffraction studies of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O were performed at the Resource Centre “X-ray Diffraction Methods” of St. Petersburg State University using a Bruker Kappa APEX DUO diffractometer operated at 45 kV and 0.6 mA and equipped with a CCD area detector. The study was done by means of a monochromatic MoKα X-radiation (λ = 0.71073 Å), frame widths of 0.5° in ω and 10 s counting time for each frame. The intensity data were reduced and corrected for Lorentz, polarization and background effects using the Bruker software APEX2 [46]. A semiempirical absorption-correction based upon the intensities of equivalent reflections was applied [47]. The unit-cell parameters were refined by least square techniques. The structures were solved and refined using ShelX program package [48] within the Olex2 shell [49]. Crystal data, data collection information and structure refinement details are given in Table 4; atom coordinates and displacement parameters are in Table 5 and Table 6, and selected interatomic distances and angles are in Table 7. All H atoms were derived from the analysis of Fourier difference electron-density maps and refined in an isotropic approximation. The H atoms forming ammonium groups have been fixed using DFIX instruction in order to maintain a reasonable geometry of the NH4 groups with Uiso(H) set to 1.5 Ueq(N) and N–H 0.86 Å. The crystals of NH4MgCl3·6H2O were found to display a non-merohedral twinning. De-twinning treatment was achieved by the application of the CrysAlisPro software [50].

2.4. High-Temperature Powder X-Ray Diffraction

In situ high-temperature powder X-ray diffraction (HTXRD) experiments of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O phases up to 540 and 260 °C (Figure 1) were done in air using a Rigaku Ultima IV powder X-ray diffractometer (CoKα1+2 radiation, 40 kV/30 mA, Bragg-Brentano geometry, PSD D-Tex Ultra) with Rigaku HT 1500 high-temperature attachment. Thin powder samples were deposited on Pt sample holders (20 × 12 × 2 mm3) from heptane suspensions. The temperature steps and the average heating rates were 10 °C and 2/3°/min, respectively; the collecting time at each temperature step was about 20 min. Silicon was used as an external standard.
It was found that NH4MgCl3·6H2O transforms to another phase at T ~ 90 °C, which is stable up to 140 °C. No reflections were observed in the powder patterns in the temperature range 160–370 °C. Above 370 °C, broad reflections of periclase, MgO, appeared. The unit-cell parameters of NH4MgCl3·6H2O and its high-temperature phase (HT phase) (Tables S1 and S2) were refined by the Rietveld method. The refinements were based on the reflections in the 2θ region 10–75°. The refinement of the unit-cell parameters was done in the temperature ranges 23–80 °C and 100–140 °C for NH4MgCl3·6H2O and HT phase, respectively (powder pattern recorded at 90 °C was excluded from the refinement due to the appearance of reflections of the HT phase).
(NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. It is interesting that the shape of reflections and their intensity is slightly different at each of the patterns recorded at different temperatures, most likely, due to some changes in the structure of the phase. Therefore, the unit-cell parameters refined by the Rietveld method in the 2θ region 10–75° and in temperature range 24–80 °C (Table S3) should be taken as approximate only.
In all cases, the Rietveld refinements were carried out using Topas 4.2 [52]; the crystallographic data of starting models used for refinement are given in Table 8. Rietveld refinements were done with the fixed atom coordinates, site scattering and isotropic-displacement parameters. The background was modelled using a Chebyshev polynomial approximation of the 18th order. The peak profile was described using the fundamental parameters approach. The main coefficients of the thermal-expansion tensor were determined using the TTT program package [53,54] and the TEV program [55].

3. Results

3.1. Chemical Composition

The chemical compositions were averaged based on 15/10 analyses for NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O, respectively. Due to the low quality of crystal surfaces and the high rate of their dehydration in vacuum, the data were normalized to 100 wt. %. The ratios between the specie-defining cations and anions were determined as NH4/Mg/Cl = 0.96/1/3.08 and NH4/Fe/Cl = 1.70/0.94/5.06 (Table 3), which is close to those in the ideal chemical formulas of the studied phases.

3.2. Crystal Structures

The crystal structure of synthetic NH4MgCl3·6H2O was described by Solans et al. [57] and Marsh [58] without localization of hydrogen atoms. Recently, the crystal structure of novograblenovite, (NH4,K)MgCl3·6H2O, was described in detail, including localization of hydrogen atoms, description of structural peculiarities and structural relationships with carnallite, KMgCl3·6H2O [10].
The crystal structure of NH4MgCl3·6H2O is based upon regular Mg(H2O)6 octahedra that are connected to Cl− anions, and indirectly to NH4+ cations, through hydrogen bonds into a three-dimensional framework (Figure 2, Table 7 and Table 9). The Mg site is octahedrally coordinated by six H2O molecules with the mean <Mg–O> bond length of 2.045 Å (Table 7). Each NH4+ ion is surrounded by six CI− ions in an octahedral arrangement with the average <Cl–N> distance of 3.330 Å (Table 7). In general, the crystal structure of NH4MgCl3·6H2O can be represented as a perovskite-like network of (NH4)Cl6 octahedra with Mg(H2O)6 octahedra localized in framework cavities. Table 10 provides the results of bond-valence analysis for NH4MgCl3·6H2O phase with bond-valence parameters taken from [59,60,61,62].
The crystal structure of kremersite, (NH4,K)2[Fe3+Cl5(H2O)], was described earlier based on the data obtained from its pure synthetic analogue, (NH4)2Fe3+Cl5·H2O [63]. It is based upon isolated FeCl5(H2O) octahedra that are connected to NH4+ cations through hydrogen bonds into a three-dimensional framework (Figure 3, Table 9). The Fe site is octahedrally coordinated by five Cl atoms and one H2O molecule with the average <Fe–Cl,O> distance of 2.325 Å (Table 7). A bond-valence calculation for (NH4)2Fe3+Cl5·H2O phase with bond-valence parameters taken from [59,60,61,62] is given in Table S4.

3.3. HTXRD

The NH4MgCl3·6H2O phase dehydrates to NH4MgCl3·2H2O (further denoted as HT phase), which is isotypic to β-Rb(MnCl3)(H2O)2 [56]. The unit-cell parameters at different temperatures are provided in Tables S1–S3 for NH4MgCl3·6H2O, NH4MgCl3·2H2O, and (NH4)2Fe3+Cl5·H2O, respectively, and are visualized in Figure 4, Figure 5 and Figure S1. The main thermal expansion coefficients for NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O were determined using linear approximations (Tables S5 and S6) of temperature dependencies of the unit-cell parameters (Table 11).
The NH4MgCl3·6H2O phase is characterized by rather strong anisotropy of thermal expansion with the αa/αb/αcratio equal to 3.2/1/2.2 (Table 11). The strongest anisotropy is observed within the xy plane (Figure 6). In contrast, thermal expansion of (NH4)2Fe3+Cl5·H2O is rather uniform with the αa/αb/αcratio equal to 1/1.1/1.2 (Table 11). The data obtained for the HT phase are less accurate with larger ESDs and only five points available for approximation (Table S5). In general, the behaviour of the HT phase at elevated temperatures can be described as a strong expansion with the thermal expansion coefficients changing abruptly, due to the rather abrupt and nonlinear changes of the unit-cell parameters (Figure S1).

4. Discussion

The crystal-structure study of the technogenic phase “kopeiskite” confirmed that (NH4)2Fe3+Cl5·H2O is a complete analogue of kremersite. The technogenic phase “redikortsevite”, NH4MgCl3·6H2O, is not a dimorph, but an direct analogue of novograblenovite, (NH4,K)MgCl3·6H2O. The only difference is the presence of K in the mineral, while the technogenic phase contains ammonium only. It is interesting that the pure potassium analogue of novograblenovite, carnallite, KMgCl3·6H2O, belongs to a different structure type [10]. The previous studies of XMgCl3·6H2O compounds (X = Li, K, NH4, Rb, Cs) [10,25,64] demonstrated that the crystal structures of the Li and K phases differ from those of the NH4, Rb and Cs phases. In contrast, for (X)2Fe3+Cl5·H2O compounds (X = K, NH4, Rb, Cs), the crystal structure of the Cs phase differs from those of the NH4, K and Rb phases. Therefore, the ionic radii have a significant impact upon the structure type in the compounds under consideration (Table 12).
The structural nature of thermal expansion anisotropy observed for NH4MgCl3·6H2O phase deserves special attention. The three-dimensional integrity of its structure is controlled by the hydrogen bonding network. Assuming that weaker bonds are more prone to stretching, one should analyse the hydrogen bonding system responsible for the linkage of Mg(H2O)6 octahedra via Cl atoms (Figure 6). The analysis of interatomic distances indicates that the Cl1–H bonds are located either along a (Cl1–H1B bond) or b (Cl1–H2A bond) axes. The Cl1–H1B distance is longer (2.50 (5) Å with the distance between two donor oxygen atoms O1…O1 equal to 6.418 Å) than the Cl1–H2A distance (2.45 (5) Å with the O2…O2 distance of 6.270 Å) (Figure 6). Therefore, the anisotropy of thermal expansion within the xy plane reflects the anisotropy of the strength of the hydrogen bonding network involving Cl atoms. Along the c axis, the Mg(H2O)6 octahedra are linked via hydrogen bonds through Cl2 atoms (Figure 6) with the Cl2–H distances ranging from 2.39 to 2.45 Å. However, the Cl2–H bonds are oriented differently (i.e., the network is not unidirectional) and thus cannot be directly compared with the Cl1–H distances. It is worthy to note that the dehydration-induced NH4MgCl3·6H2O → NH4MgCl3·2H2O transformation is associated with restructuring of the coordination sphere of the NH4+ cations. The latter are coordinated mainly by H2O molecules in the high hydrated phase, whereas, in the dihydrate, the coordination is mostly by the Cl− anions. For NH4MgCl3·6H2O, the hydrogen bonding network plays a crucial role in the structural stability and the character of the physical properties such as thermal expansion. For (NH4)2Fe3+Cl5·H2O, no preferred orientation of the Cl–H bonds is observed, resulting in the absence of thermal expansion anisotropy.

5. Conclusions

The study of the technogenic NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O phases from the burned dumps of the Chelyabinsk coal basin shows that they are complete analogues of novograblenovite and kremersite, respectively. In contrast to the two minerals, the technogenic phases do not contain K and are almost pure ammonium compounds. As was shown earlier [10], and confirmed in the present study, structural integrity of the studied phases is determined by the hydrogen bonding networks that serve as the most important intermediates providing linkage between main structural units. The distribution of the hydrogen bonds also explains the high-temperature behaviour of the crystal structures of the compounds under consideration and therefore determines their physical properties.
The analogy between the two studied phases and their natural counterparts, novograblenovite and kremersite, points to the geochemical analogy between technogenic (burned coal dumps) and natural (volcanic fumaroles) environments. Thus, one may expect the discoveries of more NH4-bearing mineral species analogous to the technogenic phases previously described by Chesnokov et al. [9] (Table 2).

Supplementary Materials

The following are available online at https://www.mdpi.com/2075-163X/9/8/486/s1, Figure S1: The dependencies of unit-cell parameters of HT modification of NH4MgCl3·2H2O, Table S1: The refined unit-cell parameters for NH4MgCl3·6H2O phase at different temperatures, Table S2: The refined unit-cell parameters for HT phase of NH4MgCl3·2H2O, at different temperatures, Table S3: The refined unit-cell parameters for (NH4)2Fe3+Cl5·H2O phase at different temperatures, Table S4: Bond-valence analysis (v.u. = valence units) for (NH4)2Fe3+Cl5·H2O phase, Table S5: Approximation equations for NH4MgCl3·6H2O phase and its HT modification, Table S6: Approximation equations for (NH4)2Fe3+Cl5·H2O phase, NH4MgCl3·6H2O.CIF: crystallographic Information file (CIF) for the crystal structure of NH4MgCl3·6H2O, (NH4)2FeCl5·H2O.CIF: crystallographic Information file (CIF) for the crystal structure of(NH4)2FeCl5·H2O.

Author Contributions

Conceptualization, A.A.Z., E.S.Z. and S.V.K.; methodology, A.A.Z. and E.S.Z.; investigation, A.A.Z., E.S.Z., M.G.K., M.A.R. and V.V.S.; writing–original draft preparation, A.A.Z. and E.S.Z.; writing–review and editing, S.V.K.; visualization, A.A.Z. and E.S.Z.

Funding

This research was funded by the Russian Foundation for Basic Research (grant No. 19-05-00628). E.S.Z. is grateful to the President Federation Grant for Young Candidates of Sciences (MK- 3246.2019.5).

Acknowledgments

The X-ray diffraction studies were performed in the X-ray Diffraction Resource Centre of St. Petersburg State University. The chemical analytical studies were done in the “Geomodel” Resource Centre of St. Petersburg State University.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Chesnokov, B.V.; Polyakov, V.O.; Bushmakin, A.F. Bazhenovite CaS5·CaS2O3·6Ca(OH)2·20H2O—A new mineral. Zap. Vseross. Miner. Obs. 1987, 116, 737–743. (In Russian) [Google Scholar]
  2. Shcherbakova, Y.P.; Bazhenova, L.F.; Chesnokov, B.V. Godovikovite—NH4(Al,Fe)(SO4)2 a new ammonium-bearing sulfate. Zap. Vseross. Miner. Obs. 1988, 117, 208–211. (In Russian) [Google Scholar]
  3. Chesnokov, B.V.; Lotova, E.V.; Nigmatullina, E.N.; Pavlutchenko, V.S.; Bushmakin, A.F. Dmisteinbergite CaAl2Si2O8 (hexagonal)—A new mineral. Zap. Vseross. Miner. Obs. 1990, 119, 43–46. (In Russian) [Google Scholar]
  4. Chesnokov, B.V.; Lotova, E.V.; Pavlyuchenko, V.S.; Usova, L.V.; Bushmakin, A.F.; Nishanbayev, T.P. Svyatoslavite CaAl2Si2O8 (orthorhombic)—A new mineral. Zap. Vseross. Miner. Obs. 1989, 118, 111–114. (In Russian) [Google Scholar]
  5. Chesnokov, B.V.; Nishanbaev, T.P.; Bazhenova, L.F. Rorisite CaFCl—A new mineral. Zap. Vseross. Miner. Obs. 1990, 119, 73–76. (In Russian) [Google Scholar]
  6. Shcherbakova, Y.P.; Bazhenova, L.F. Efremovite (NH4)2Mg2(SO4)3—Ammonium analogue of langbeinite—A new mineral. Zap. Vseross. Miner. Obs. 1989, 118, 84–87. (In Russian) [Google Scholar]
  7. Chesnokov, B.V.; Bazhenova, L.F. Srebrodolskite Ca2Fe2O5—A new mineral. Zap. Vseross. Miner. Obs. 1985, 114, 195–199. (In Russian) [Google Scholar]
  8. Chesnokov, B.V.; Bazhenova, L.F.; Bushmakin, A.F. Fluorellestadite Ca10[(SO4),(SiO4)]6F2—A new mineral. Zap. Vseross. Miner. Obs. 1987, 116, 743–746. (In Russian) [Google Scholar]
  9. Chesnokov, B.V.; Shcherbakova, E.P.; Nishanbaev, T.P. Minerals of Burnt Dumps of the Chelyabinsk Coal Basin; Ural branch of RAS: Miass, Russia, 2008; pp. 1–139. (In Russian) [Google Scholar]
  10. Okrugin, V.M.; Kudaeva, S.S.; Karimova, O.V.; Yakubovich, O.V.; Belakovskiy, D.I.; Chukanov, N.V.; Zolotarev, A.A.; Gurzhiy, V.V.; Zinovieva, N.G.; Shiryaev, A.A.; et al. The new mineral novograblenovite, (NH4,K)MgCl3·6H2O from the Tolbachik volcano, Kamchatka, Russia: Mineral information and crystal structure. Miner. Mag. 2019, 83, 223–231. [Google Scholar] [CrossRef]
  11. Demartin, F.; Gramaccioli, C.M.; Campostrini, I. Pyracmonite, (NH4)3Fe(SO4)3, a new ammonium iron sulfate from La Fossa crater, Vulcano, Aeolian Islands, Italy. Can. Miner. 2010, 48, 307–313. [Google Scholar] [CrossRef]
  12. Galuskina, I.O.; Lazic, B.; Armbruster, T.; Galuskin, E.V.; Gazeev, V.M.; Zadov, A.E.; Pertsev, N.N.; Jezak, L.; Wrzalik, R.; Gurbanov, A.G. Kumtyubeite Ca5(SiO4)2F2—A new calcium mineral of the humite group from Northern Caucasus, Kabardino-Balkaria, Russia. Am. Miner. 2009, 94, 1361–1370. [Google Scholar] [CrossRef]
  13. Galuskina, I.O.; Vapnik, Y.; Lazic, B.; Armbruster, T.; Murashko, M.; Galuskin, E.V. Harmunite CaFe2O4: A new mineral from the Jabel Harmun, West Bank, Palestinian Autonomy, Israel. Am. Miner. 2014, 99, 965–975. [Google Scholar] [CrossRef]
  14. Rossi, M.; Nestola, F.; Zorzi, F.; Lanza, A.; Peruzzo, L.; Guastoni, A.; Kasatkin, A. Ghiaraite: A new mineral from Vesuvius volcano, Naples (Italy). Am. Miner. 2014, 99, 519–524. [Google Scholar] [CrossRef]
  15. Murashko, M.N.; Pekov, I.V.; Krivovichev, S.V.; Chernyatyeava, A.P.; Yapaskurt, V.O.; Zadov, A.E.; Zelensky, M.E. Steklite, KAl(SO4)2: The find at Tolbachik volcano (Kamchatka, Russia). Validation as a mineral species and crystal structure. Zap. Vseross. Min. Obs. 2012, 141, 36–44. (In Russian) [Google Scholar]
  16. Galuskina, I.O.; Galuskin, E.V.; Pakhomova, A.S.; Widmer, R.; Armbruster, T.; Krüger, B.; Grew, E.S.; Vapnik, Y.; Dzierażanowski, P.; Murashko, M. Khesinite, Ca4Mg2Fe3+10O4[(Fe3+10Si2)O36], a new rhönite-group (sapphirine supergroup) mineral from the Negev Desert, Israel—Natural analogue of the SFCA phase. Eur. J. Miner. 2017, 29, 101–116. [Google Scholar] [CrossRef]
  17. Galuskin, E.V.; Galuskina, I.O.; Lazic, B.; Armbruster, T.; Zadov, A.E.; Krzykawski, T.; Banasik, K.; Gazeev, V.M.; Pertsev, N.N. Rusinovite, Ca10(Si2O7)3Cl2: A new skarn mineral from the Upper Chegem caldera, Kabardino-Balkaria, Northern Caucasus, Russia. Eur. J. Miner. 2011, 23, 837–844. [Google Scholar] [CrossRef]
  18. Rose, H. Ueber den carnallit. Ann. der Phys. und Chem. 1856, 98, 161–163. (In Russian) [Google Scholar] [CrossRef]
  19. Chesnokov, B.V.; Bazhenova, L.F.; Shcherbakova, E.P.; Michal, T.A.; Deriabina, T.N. New minerals from the burned dumps of the Chelyabinsk coal basin, in Mineralogy, Technogenesis, and Mineral-Resource Complexes of the Urals. Akad. Nauk SSSR-Uralskoe Otdel. 1988, 5, 31. (In Russian) [Google Scholar]
  20. Witzke, T. Die Minerale der brennenden Halde der Steinkohlengrube “Deutschlandschacht” in Oelsnitz bei Zwickau. Aufschluss 1996, 47, 41–48. (In German) [Google Scholar]
  21. Stachowicz, M.; Parafiniuk, J.; Baginski, B.; Macdonald, R.; Wozniak, K. Structural analysis of new mineral phases. Acta Cryst. 2011, A67, C573. [Google Scholar] [CrossRef]
  22. Kremers, P. Ueber die aschenbestandtheile und die producte der trocknen destillation bei Braun und Steinkohlen. Ann. der Phys. und Chem. 1851, 84, 67–80. (In German) [Google Scholar] [CrossRef]
  23. Scacchi, A. Notizie preliminari di alcune specie mineralogiche rinvenute nel Vesuvio dopo l’incendio di aprile. Rend. Sci. Fis. Mat. Napoli 1872, 11, 210–213. (In Italian) [Google Scholar]
  24. Ackermann, M.; Brüning, D.; Lorenz, T.; Becker, P.; Bohatý, L. Thermodynamic properties of the new multiferroic material (NH4)2[FeCl5(H2O)]. New J. Phys. 2013, 15, 3001. [Google Scholar] [CrossRef]
  25. Ackermann, M.; Lorenz, T.; Becker, P.; Bohat ý, L. Magnetoelectric properties of A2[FeCl5(H2O)] with A = K., Rb, Cs. J. Phys-Condens. Mat. 2014, 26, 506002. [Google Scholar] [CrossRef] [PubMed]
  26. Demartin, F.; Castellano, C.; Campostrini, I. Acmonidesite, a new ammonium sulfate chloride from La Fossa crater, Vulcano, Aeolian Islands, Italy. Miner. Mag. 2019, 83, 137–142. [Google Scholar] [CrossRef]
  27. Kampf, A.R.; Nash, B.P.; Adams, P.M.; Marty, L.; Hughes, J.M. Ammoniolasalite, [(NH4)2Mg2(H2O)20][V10O28], A New Decavanadate Species from the Burro Mine, Slick Rock District, Colorado. Can. Miner. 2018, 56, 859–869. [Google Scholar] [CrossRef]
  28. Kampf, A.R.; Plášil, J.; Nash, B.P.; Marty, J. Ammoniomathesiusite, a new uranyl sulfate–vanadate mineral from the Burro mine, San Miguel County, Colorado, USA. Mineral. Mag. 2019, 83, 115–121. [Google Scholar] [CrossRef]
  29. Kampf, A.R.; Nash, B.P.; Hughes, J.M.; Marty, J. Burroite, Ca2(NH4)2(V10O28)·15H2O, a New Decavanadate Mineral from the Burro Mine, San Miguel County, Colorado. Can. Mineral. 2017, 55, 473–481. [Google Scholar] [CrossRef]
  30. Zhitova, E.S.; Siidra, O.I.; Belakovsky, D.I.; Shilovskikh, V.V.; Nuzhdaev, A.A.; Ismagilova, R.M. Ammoniovoltaite, (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18, a new mineral from the Severo-Kambalny geothermal field, Kamchatka, Russia. Mineral. Mag. 2018, 82, 1057–1077. [Google Scholar] [CrossRef]
  31. Kampf, A.R.; Plášil, J.; Olds, T.A.; Nash, B.P.; Marty, J. Ammoniozippeite, a New Uranyl Sulfate Mineral from the Blue Lizard Mine, San Juan County, Utah, and the Burro Mine, San Miguel County, Colorado, USA. Can. Mineral. 2018, 56, 235–245. [Google Scholar] [CrossRef]
  32. Olds, T.A.; Plášil, J.; Kampf, A.R.; Burns, P.C.; Nash, B.P.; Marty, J.; Rose, T.P.; Carlson, S.M. Redcanyonite, (NH4)2Mn[(UO2)4O4(SO4)2](H2O)4, a new zippeite-group mineral from the Blue Lizard mine, San Juan County, Utah, USA. Mineral. Mag. 2018, 82, 1261–1275. [Google Scholar] [CrossRef]
  33. Kampf, A.R.; Chukanov, N.V.; Möhn, G.; Dini, M.; Donoso, A.A.; Friis, H. Cuatrocapaite-(NH4) and cuatrocapaite-(K), two new minerals from the Torrecillas mine, Iquique Province, Chile, related to lucabindiite and gajardoite. Mineral. Mag. 2019, 1–24. [Google Scholar] [CrossRef]
  34. Kampf, A.R.; Cooper, M.A.; Rossman, G.R.; Nash, B.P.; Hawthorne, F.C.; Marty, J. Davidbrownite, IMA 2018-129. CNMNC Newsletter No. 47, February 2019, page 203. Eur. J. Mineral. 2019, 31, 199–204. [Google Scholar]
  35. Kampf, A.R.; Celestian, A.J.; Nash, B.P.; Marty, J. Phoxite, (NH4)2Mg2(C2O4)(PO3OH)2(H2O)4, the first phosphate-oxalate mineral. Am. Mineral. 2019, 104, 973–979. [Google Scholar] [CrossRef]
  36. Kampf, A.R.; Cooper, M.A.; Nash, B.P.; Cerling, T.E.; Marty, J.; Hummer, D.R.; Celestian, A.J.; Rose, T.P.; Trebisky, T.J. Rowleyite, [Na(NH4,K)9Cl4][V25+,4+(P,As)O8]6·n[H2O,Na,NH4,K,Cl], a new mineral with a microporous framework structure. Am. Mineral. 2017, 102, 1037–1044. [Google Scholar]
  37. Chukanov, N.V.; Pekov, I.V.; Sejkora, J.; Plášil, J.; Belakovskiy, D.I.; Britvin, S.N. Ferrierite-NH4, (NH4,Mg0.5)5(Al5Si31O72)·22H2O, A New Zeolite From Northern Bohemia, Czech Republic. Can. Mineral. 2019, 55, 81–90. [Google Scholar] [CrossRef]
  38. Kampf, A.R.; Plášil, J.; Nash, B.P.; Marty, J. Greenlizardite, (NH4)Na(UO2)2(SO4)2(OH)2·4H2O, a new mineral with phosphuranylite-type uranyl sulfate sheets from Red Canyon, San Juan County, Utah, USA. Mineral. Mag. 2018, 82, 401–411. [Google Scholar] [CrossRef]
  39. Kampf, A.R.; Plášil, J.; Nash, B.P.; Marty, J. Meitnerite, (NH4)(UO2)(SO4)(OH)·2H2O, a new uranyl-sulfate mineral with a sheet structure. Eur. J. Mineral. 2018, 30, 999–1006. [Google Scholar] [CrossRef]
  40. Chukanov, N.V.; Pekov, I.V.; Belakovskiy, D.I.; Britvin, S.N.; Stergiou, V.; Voudouris, P.; Magganas, A. Katerinopoulosite, (NH4)2Zn(SO4)2·6H2O, a new mineral from the Esperanza mine, Lavrion, Greece. Eur. J. Mineral. 2018, 30, 821–826. [Google Scholar] [CrossRef]
  41. Campostrini, I.; Demartin, F.; Scavini, M. Russoite, NH4ClAs23+O3(H2O)0.5, a new phylloarsenite mineral from Solfatara Di Pozzuoli, Napoli, Italy. Mineral. Mag. 2019, 83, 89–94. [Google Scholar] [CrossRef]
  42. Parafiniuk, J.; Kruszewski, Ł. Ammonium minerals from burning coal-dumps of the Upper Silesian Coal Basin (Poland). Geol. Quart. 2009, 53, 341–356. [Google Scholar]
  43. Siidra, O.I.; Lukina, E.A.; Nazarchuk, E.V.; Depmeier, W.; Bubnova, R.S.; Agakhanov, A.A.; Avdontseva, E.Y.; Filatov, S.K.; Kovrugin, V.M. Saranchinaite, Na2Cu(SO4)2, a new ehalative mineral from Tolbachik volcano, Kamchatka, Russia, and a product of the reversible dehydration of krönkeite, Na2Cu(SO4)2(H2O)2. Mineral. Mag. 2018, 82, 257–274. [Google Scholar] [CrossRef]
  44. Siidra, O.I.; Borisov, A.S.; Lukina, E.A.; Depmeier, W.; Platonova, N.V.; Colmont, M.; Nekrasova, D.O. Reversible hydration/dehydration and thermal expansion of euchlorine, ideally KNaCu3O(SO4)3. Phys. Chem. Miner. 2019, 46, 403–416. [Google Scholar] [CrossRef]
  45. Zhitova, E.S.; Sergeeva, A.V.; Nuzhdaev, A.A.; Krzhizhanovskaya, M.G.; Chubarov, V.M. Tschermigite from thermal fields of Southern Kamchatka: high-temperature transformation and peculiarities of IR-spectrum. Zap. Ross. Mineral. Obs. 2019, 148. [Google Scholar]
  46. Bruker-AXS. APEX2; Version 2014.11-0; Bruker-AXS: Madison, WI, USA, 2014. [Google Scholar]
  47. Sheldrick, G.M. SADABS; University of Goettingen: Goettingen, Germany, 2007. [Google Scholar]
  48. Sheldrick, G.M. Crystal structure refinement with SHELXL. Acta Crystallogr. 2015, C71, 3–8. [Google Scholar]
  49. Dolomanov, O.V.; Bourhis, L.J.; Gildea, R.J.; Howard, J.A.K.; Puschmann, H. OLEX2: A complete structure solution, refinement and analysis program. J. Appl. Crystallogr. 2009, 42, 339–341. [Google Scholar] [CrossRef]
  50. CrysAlisPro Software System, version 1.171.39.44; Rigaku Oxford Diffraction: Oxford, UK, 2015.
  51. Momma, K.; Izumi, F. VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J. Appl. Crystallogr. 2011, 44, 1272–1276. [Google Scholar] [CrossRef]
  52. Topas V.4.2. General Profile and Structure Analysis Software for Powder Diffraction Data; Bruker-AXS: Karlsruhe, Germany, 2009.
  53. Belousov, R.; Filatov, S.K. Algorithm for Calculating the Thermal Expansion Tensor and Constructing the Thermal Expansion Diagram for Crystals. Glass Phys. Chem. 2007, 33, 271–275. [Google Scholar] [CrossRef]
  54. Bubnova, R.S.; Firsova, V.A.; Filatov, S.K. Software for determining the thermal expansion tensor and the graphic representation of its characteristic surface (theta to tensor-TTT). Glass Phys. Chem. 2013, 39, 347–350. [Google Scholar] [CrossRef]
  55. Langreiter, T.; Kahlenberg, V. TEV—A Program for the Determination of the Thermal Expansion Tensor from Diffraction Data. Crystals 2015, 5, 143–153. [Google Scholar] [CrossRef]
  56. Jensen, S.J.; Lehmann, M.S. Neutron diffraction study of β-RbMnCl3·2H2O. Acta Chem. Scand. 1970, 24, 3422–3424. [Google Scholar] [CrossRef]
  57. Solans, X.; Font-Altaba, M.; Aguiló, M.; Solans, J.; Domenech, V. Crystal form and structure of ammonium hexaaquamagnesium trichloride, NH4[Mg(H2O)6]Cl3. Acta Crystallogr. 1983, C39, 1488–1490. [Google Scholar] [CrossRef]
  58. Marsh, R.E. Structure of MgCl2.RbCl·6H2O. Corrigendum. Acta Crystallogr. 1992, C48, 218–219. [Google Scholar] [CrossRef]
  59. Brown, I.D.; Altermatt, D. Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database. Acta Crystallogr. 1985, B41, 244–247. [Google Scholar] [CrossRef]
  60. Brese, N.E.; O’Keeffe, M. Bond-valence parameters for solids. Acta Crystallogr. 1991, B47, 192–197. [Google Scholar] [CrossRef]
  61. Malcherek, T.; Schlueter, J. Cu3MgCl2(OH)6 and the bond-valence parameters of the OH–Cl bond. Acta Crystallogr. 2007, B63, 157–160. [Google Scholar] [CrossRef]
  62. Brown, D.I. The Chemical Bond in Inorganic Chemistry: the bond valence model. In International Union of Crystallography Monographs on Crystallography; Oxford University Press: Oxford, UK, 2002; pp. 1–230. [Google Scholar]
  63. Figgis, B.N.; Raston, C.L.; Sharma, R.P.; White, A.H. Crystal structure of diammonium aquapentachloroferrate (III). Aust. J. Chem. 1978, 31, 2717–2720. [Google Scholar] [CrossRef]
  64. Waizumi, K.; Masuda, H.; Ohtaki, H.; Scripkin, M.Y.; Burkov, K.A. Crystallographic investigations of [Mg(H2O)6]XCl3 double salts (X+=K+,Rb+,Cs+,NH4+): Crystal structure of [Mg(H2O)6]XCl3. Am. Mineral. 1991, 76, 1884–1888. [Google Scholar]
  65. Schlemper, E.O.; Sen Gupta, P.K.; Zoltai, T. Refinement of the structure of carnallite, Mg(H2O)6KCl3. Am. Mineral. 1985, 70, l309–l313. [Google Scholar]
  66. Schmidt, H.; Euler, B.; Voigta, W.; Heide, G. Lithium carnallite, LiCl·MgCl2·7H2O. Acta Crystallogr. 2009, C65, 57–59. [Google Scholar] [CrossRef]
  67. O’Connor, C.J.; Deaver, B.S., Jr.; Sinn, E. Crystal structures of A2FeCl5·H2O (A=Rb+, Cs+) and field dependent superconducting susceptometer measurements. J. Chem. Phys. 1979, 70, 5161. [Google Scholar] [CrossRef]
  68. Bellanca, A. La struttura dell’eritrosiderite. Period. Mineral. 1948, 17, 59–72. (In Italian) [Google Scholar]
  69. Shannon, R.D. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. 1976, A32, 751–767. [Google Scholar] [CrossRef]
  70. Sidey, V. On the effective ionic radii for ammonium. Acta Crystallogr. 2016, B72, 626–633. [Google Scholar] [CrossRef]
Minerals 09 00486 g001 550
Figure 1. Powder X-ray diffraction pattern recorded for NH4MgCl3·6H2O up to 540 °C.
Figure 1. Powder X-ray diffraction pattern recorded for NH4MgCl3·6H2O up to 540 °C.
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Figure 2. The crystal structure and hydrogen bonding of NH4MgCl3·6H2O phase.
Figure 2. The crystal structure and hydrogen bonding of NH4MgCl3·6H2O phase.
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Figure 3. The crystal structure and hydrogen bonding of (NH4)2FeCl5·H2O phase.
Figure 3. The crystal structure and hydrogen bonding of (NH4)2FeCl5·H2O phase.
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Figure 4. The dependencies of the unit-cell parameters versus temperature for NH4MgCl3·6H2O phase.
Figure 4. The dependencies of the unit-cell parameters versus temperature for NH4MgCl3·6H2O phase.
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Figure 5. The dependencies of the unit-cell parameters versus temperature for (NH4)2Fe3+Cl5·H2O phase.
Figure 5. The dependencies of the unit-cell parameters versus temperature for (NH4)2Fe3+Cl5·H2O phase.
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Figure 6. The crystal structure of NH4MgCl3·6H2O and a section of the figure of thermal expansion coefficients oriented relative to the crystallographic axes (ammonium is excluded for simplicity).
Figure 6. The crystal structure of NH4MgCl3·6H2O and a section of the figure of thermal expansion coefficients oriented relative to the crystallographic axes (ammonium is excluded for simplicity).
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Table
Table 1. Recently discovered ammonium minerals.
Table 1. Recently discovered ammonium minerals.
MineralLocality, Scenarios of FormationReference
Acmonidesite
(NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8		La Fossa Crater, Vulcano, Aeolian Islands, Sicily, Italy. Fumarolic phase, (T ~ 250 °C).[26]
Ammoniolasalite
[(NH4)2Mg2(H2O)20]·[V10O28]		Burro Mine, San Miguel County, Utah, USA.
Secondary phases.		[27]
Ammoniomathesiusite
(NH4)5(UO2)4(SO4)4(VO5)·4H2O		[28]
Burroite
Ca2(NH4)2(V10O28)·15H2O		[29]
Ammoniovoltaite
(NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18		Severo-Kambalny geothermal field, southern Kamchatka, Russia. Efflorescence around gas-steam hydrothermal vents.[30]
Ammoniozippeite
(NH4)2[(UO2)2(SO4)O2]·H2O		Blue Lizard Mine, San Juan County, Utah, and the Burro Mine, San Miguel County, Colorado, USA. Low-temperature, secondary phase within organic-rich beds.[31]
Redcanyonite
(NH4)2Mn[(UO2)4O4(SO4)2](H2O)4		[32]
Cuatrocapaite-(NH4)
(NH4)3(NaM☐)(As2O3)6Cl6·16H2O		Torrecillas Mine, Salar Grande, Iquique Province, Tarapacá Region, Chile.[33]
Davidbrownite-(NH4) (NH4)5(V4+O)2(C2O4)[PO2.75(OH)1.25]4·3H2ORowley Mine, Painted Rock Mts, Arizona, USA. Low-temperature, apparently post-mining suite of phases that include various vanadates, phosphates, oxalates and chlorides, some containing NH4+.[34]
Phoxite (NH4)2Mg2(C2O4)(PO3OH)2(H2O)4[35]
Rowleyite
[Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6·n[H2O,Na, NH4,K,Cl]		[36]
Ferrierite-NH4
(NH4,Mg0.5)5(Al5Si31O72)·22H2O		Northern Bohemia, Czech Republic.[37]
Greenlizardite
(NH4)Na(UO2)2(SO4)2(OH)2·4H2O		Green Lizard Mine, Red Canyon, San Juan County, Utah, USA. Secondary alteration phase.[38]
Meitnerite
(NH4)(UO2)(SO4)(OH)·2H2O		[39]
Katerinopoulosite
(NH4)2Zn(SO4)2·6H2O		Esperanza Mine, Lavrion District, Attikí Prefecture, Greece. Oxidation zone of a sphalerite-rich orebody.[40]
Novograblenovite
(NH4,K)MgCl3·6H2O		2012–2013 Tolbachik effusive eruption basalts, Plosky Tolbachik volcano, Kamchatka Oblast, Far-Eastern Region, Russia. Exhalation due to volcanic gas exposure.[10]
Russoite
(NH4)ClAs2O3(H2O)0.5		Solfatara di Pozzuoli, Pozzuoli, Napoli, Italy. Fumarolic phase.[41]
Table
Table 2. Ammonium phases described in the burned dumps of the Chelyabinsk coal basin by Chesnokov et al. [9].
Table 2. Ammonium phases described in the burned dumps of the Chelyabinsk coal basin by Chesnokov et al. [9].
Ideal Chemical FormulaMineral Analogue If KnownChesnakov’s Name
NH4Clsalammoniac
NH4MgCl3·6H2Onovograblenoviteredikortsevite
(NH4)2Fe3+Cl5·H2Okremersitekopeiskite
(NH4)2Mg2(SO4)3efremovite 1efremovite
(NH4)Al(SO4)2godovikovite 1godovikovite
NH4Fe3+3(SO4)2(OH)6ammoniojarosite
(NH4)2Mg(SO4)2·6H2Oboussingaultite
(NH4)2Ca(SO4)2·H2Okoktaite
(NH4)Fe3+(SO4)2sabieiteterriconite
(NH4)2SO4mascagnite
(NH4)3Fe3+(SO4)3pyracmonite(NH4)3Fe3+(SO4)3
(NH4)2Fe2+(SO4)2·6H2Omohrite
NH4Al(SO4)2·12H2Otschermigite
NH4Fe3+(SO4)2·12H2Olonecreekite
NH4Al(SO4)2·4H2O-NH4Al(SO4)2·4H2O
(NH4)2Mg(SO4)2·4H2O-ammonioleonite
1 Chelyabinsk coal basin is the type of locality of the mineral.
Table
Table 3. Chemical composition of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O.
Table 3. Chemical composition of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O.
NH4MgCl3·6H2O(NH4)2Fe3+Cl5·(H2O)Standard
ConstituentWt. %Atoms Per Formula Unit 3ConstituentWt. %Atoms Per Formula Unit 4
(NH4)2O 19.680.96(NH4)2O 115.961.70BN (N)
MgO15.611.00Fe2O327.190.94MgO (Mg)
FeS2 (Fe)
Cl42.343.08Cl64.645.06NaCl (Cl)
H2O 241.936.00H2O (2)6.501.00
Cl2=O–9.55 Cl2=O−14.29
Total100.00 Total100.00
1 Nitrogen (ammonium) content can be taken as approximate due to problems with measuring elements with Z < 8 using energy-dispersive spectroscopy; 2 calculated from the crystal-structure data; 3 calculated on the basis of Mg = 1; 4 calculated on the basis of Fe + Cl = 6.
Table
Table 4. Crystal data and structure refinement for NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·(H2O).
Table 4. Crystal data and structure refinement for NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·(H2O).
CompoundNH4MgCl3·6H2O(NH4)2FeCl5·H2O
Crystal systemmonoclinicorthorhombic
Space groupC2/cPnma
a, Å9.3091(9)13.725(2)
b, Å9.5353(7)9.9365(16)
c, Å13.2941(12)7.0370(11)
β, °90.089(8)-
V, Å31180.05(18)959.7(3)
Z44
ρcalc, g/cm31.4451.988
μ, mm−10.8222.900
F(000)536.0572.0
RadiationMoKα (λ = 0.71073)MoKα (λ = 0.71073)
2θ range, deg.8.55–59.995.936–71.776
Index ranges−13 ≤ h ≤ 12, −13 ≤ k ≤ 13,
−18 ≤ l ≤ 18		−18 ≤ h ≤ 21, −13 ≤ k ≤ 16,
−11 ≤ l ≤ 11
Reflections collected550411813
Independent reflections1678 (Rint = 0.066, Rsigma = 0.037)2256 (Rint = 0.0230, Rsigma = 0.0173)
Data/restraints/parameters1678/4/842256/7/65
Goodness of Fit1.2431.091
Final R indexes (I ≥ 2σ(I))R1 = 0.0783, wR2 = 0.1847R1 = 0.0229, wR2 = 0.0660
Final R indexes (all data)R1 = 0.0883, wR2 = 0.1907R1 = 0.0292, wR2 = 0.0690
Largest diff. peak/hole / e Å−30.53/−0.320.34/−0.80
Table
Table 5. Atomic coordinates and equivalent isotropic displacement parameters (Å2). Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor.
Table 5. Atomic coordinates and equivalent isotropic displacement parameters (Å2). Ueq is defined as 1/3 of the trace of the orthogonalised UIJ tensor.
AtomxyzUeq
NH4MgCl3·6H2O
Cl10.50.50.50.0414(3)
Cl20.7542(1)0.73838(9)0.74664(6)0.0401(3)
Mg00.50.50.0225(3)
N0.50.5012(6)0.750.061(1)
HA0.496(4)0.454(2)0.8028(7)0.053
HB0.429(4)0.560(3)0.749(3)0.053
O10.1795(3)0.6010(3)0.4481(2)0.0420(6)
O20.4099(3)0.1877(3)0.5379(2)0.0398(6)
O30.9089(3)0.5131(3)0.3603(2)0.0403(6)
H1A0.198(5)0.652(5)0.404(4)0.06(1)
H1B0.250(5)0.58105(4)0.463(3)0.04(1)
H2A0.440(6)0.248(5)0.515(4)0.05(1)
H2B0.360(5)0.193(5)0.586(4)0.05(1)
H3A0.890(6)0.447(6)0.329(4)0.06(2)
H3B0.885(5)0.579(5)0.332(3)0.04(1)
(NH4)2FeCl5·H2O
N0.14167(9)0.0006(1)0.6594(2)0.0360(2)
HA0.191(1)0.050(2)0.671(2)0.054
HB0.114(1)0.05(2)0.771(2)0.054
HC0.119(1)0.053(2)0.585(2)0.054
HD0.148(1)−0.075(2)0.614(2)0.054
Fe0.11623(2)0.250.18959(2)0.02252(6)
Cl10.10486(2)0.01065(3)0.17604(4)0.03113(8)
Cl20.00609(3)0.250.45303(6)0.03264(9)
Cl30.24790(3)0.250.39805(5)0.02664(8)
Cl40.22324(3)0.25−0.07176(6)0.0340(1)
O1−0.0033(1)0.250.0011(2)0.0388(3)
H1−0.028(2)0.184(2)−0.033(3)0.072(7)
Table
Table 6. Anisotropic displacement atom parameters (Å2).
Table 6. Anisotropic displacement atom parameters (Å2).
AtomU11U22U33U23U13U12
NH4MgCl3·6H2O
Cl10.0346(6)0.0335(6)0.0561(8)0.0098(4)−0.0010(5)−0.0015(4)
Cl20.0503(5)0.0378(5)0.0323(5)0.0002(3)−0.0001(3)0.0102(3)
Mg0.0214(7)0.0227(6)0.0234(7)0.0006(4)−0.0011(5)−0.0007(4)
N0.058(3)0.063(4)0.062(4)0−0.003(3)0
O10.023(1)0.056(2)0.048(2)0.020(1)−0.002(1)−0.008(1)
O20.049(2)0.025(1)0.046(2)0.002(1)0.018(1)0.006(1)
O30.057(2)0.033(1)0.031(1)0.002(1)−0.020(1)0.002(1)
(NH4)2FeCl5·H2O
N0.0369(5)0.0319(6)0.0392(6)0.0037(4)−0.0035(3)−0.0013(4)
Fe0.0229(1)0.0197(1)0.0250(1)0−0.00326(7)0
Cl10.0353(1)0.0186(1)0.0395(2)−0.00229(9)−0.0073(1)−0.00072(9)
Cl20.0282(2)0.0307(2)0.0390(2)00.0085(1)0
Cl30.0244(1)0.0293(2)0.0263(2)0−0.0054(1)0
Cl40.0398(2)0.0372(2)0.0250(2)00.0054(1)0
O10.0370(6)0.0240(6)0.0553(9)0−0.0237(6)0
Table
Table 7. Selected bond lengths (Å) and angles (°) in the crystal structure of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O.
Table 7. Selected bond lengths (Å) and angles (°) in the crystal structure of NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O.
NH4MgCl3·6H2O
Mg–OCl–N∠ H–N–H in NH4
Mg–O12.052(2) ×2Cl1–N3.3235(4) ×2HA–N–HB110(2)
Mg–O22.040(2) ×2Cl2–N3.273(5) ×2HA–N–HA 1115(3)
Mg–O32.044(2) ×2Cl2 2–N3.394(5) ×2HB–N–HB 1100(6)
<Mg–O>2.045<Cl–N>3.330HA–N–HB 1111(2)
Di40.00153Di40.01269
∠ H–O–H in H2O
H1A–O1–H1B106(4)
H2A–O2–H2B120(5)
H3A–O3–H3B110(5)
(NH4)2FeCl5·H2O
Fe–Cl,O∠ H–O–H in H2O∠ H–N–H in NH4
Fe–Cl12.3853(5) ×2H1–O1–H1 3115(3)HA–N–HB104(1)
Fe–Cl22.3920(5) HA–N–HC90(2)
Fe–Cl32.3276(5) HA–N–HD118(2)
Fe–Cl42.3537(5) HB–N–HC113(2)
Fe–O12.109(1) HB–N–HD116(2)
<Fe–Cl,O>2.325 HC–N–HD112(2)
Di40.03097
1 1 − x, y, 1.5 − z; 2 x + 0.5, y + 0.5; 3 x, 0.5 − y, z; 4 Di is distortion index, D i = 1 n ∑ i = 1 n | l i − l a v | l a v [51].
Table
Table 8. Crystallographic data used as starting models for the refinement of NH4MgCl3·6H2O, its HT phase and of the (NH4)2FeCl5·H2O phase by the Rietveld method.
Table 8. Crystallographic data used as starting models for the refinement of NH4MgCl3·6H2O, its HT phase and of the (NH4)2FeCl5·H2O phase by the Rietveld method.
NH4MgCl3·6H2Oβ-Rb(MnCl3)·2H2O 1 (Isotypic to HT Modification of NH4MgCl3·6H2O)(NH4)2FeCl5·H2O
SymmetryMonoclinicTriclinicOrthorhombic
Space groupC2/cP−1Pnma
a (Å)9.3091(9)6.6513.725(2)
b (Å)9.5353(7)7.019.9365(16)
c (Å)13.2941(12)9.037.0370(11)
α (°)9092.390
β (°)90.089(8)109.490
γ (°)90112.990
V (Å3)1180.05(18)358.74959.7(3)
Referencethis work[56]this work
1 In the process of refinement Rb was replaced by N, and Mn was replaced by Mg, leading to the chemical formula NH4MgCl3·2H2O.
Table
Table 9. Hydrogen bonds of NH4MgCl3·6H2O and (NH4)2FeCl5·H2O.
Table 9. Hydrogen bonds of NH4MgCl3·6H2O and (NH4)2FeCl5·H2O.
D–H d(D–H) (Å)d(H..A) (Å)<DHA (°) d(D..A) (Å)A
NH4MgCl3·6H2O
O1–H1A0.7832.395166.883.164Cl2 1
O1–H1B0.7012.514171.803.209Cl1
O2–H2A0.7102.472156.343.135Cl1
O2–H2B0.7942.390167.423.169Cl2 2
O3–H3A0.7732.435161.923.178Cl2 3
O3–H3B0.7622.411164.463.152Cl2 4
N–HA0.8342.659137.703.224Cl1 5
N–HB0.8632.414174.623.274Cl2 5
(NH4)2FeCl5·H2O
O1–H10.7752.424173.293.195Cl1 6
N–HA0.8422.862132.123.483Cl1 7
N–HA0.8422.873123.803.414Cl3
N–HA0.8422.726128.123.313Cl4 8
N–HB0.8722.855156.623.672Cl1 8
N–HC0.8062.907125.713.440Cl1
N–HC0.8062.662158.113.423Cl2
N–HC0.8062.947119.253.414Cl3
N–HD0.8182.784123.533.307Cl2 9
N–HD0.8182.802145.153.505Cl4 7
1x − 1/2, −y + 3/2, z − 1/2; 2 x − 1/2, y − 1/2, z; 3 x, −y + 1, z − 1/2; 4 –x + 3/2, −y + 3/2, −z + 1; 5 –x + 1, y, −z + 3/2; 6 −x, −y, −z; 7 –x + 1/2, −y, z + 1/2; 8 x, y, z + 1; 9 −x, −y, −z + 1.
Table
Table 10. Bond-valence analysis (v.u. = valence units) for NH4MgCl3·6H2O phase.
Table 10. Bond-valence analysis (v.u. = valence units) for NH4MgCl3·6H2O phase.
AtomNH4MgH1AH1BH2AH2BH3AH3BTotal
O1 0.38↓ ×20.800.87 2.05
O2 0.39↓ ×2 0.860.79 2.04
O3 0.39↓ ×2 0.810.822.02
Cl10.16↓ → ×2 0.11 → × 20.12 → × 2 0.78
Cl20.18↓ ×2
0.13↓ ×2		 0.13 0.140.130.130.84
Total0.962.320.930.980.980.930.940.95
Table
Table 11. The main characteristics of thermal expansion of NH4MgCl3·6H2O, its HT phase and (NH4)2Fe3+Cl5·H2O phase (°C−1, ×10−6).
Table 11. The main characteristics of thermal expansion of NH4MgCl3·6H2O, its HT phase and (NH4)2Fe3+Cl5·H2O phase (°C−1, ×10−6).
NH4MgCl3·6H2OHT Phase 1(NH4)2Fe3+Cl5·H2O
α1136.3−30.740.8
α2211.5161.145.9
α3325.2275.247.0
<α11a12.870.7-
<α22b-24.3-
<α33c12.735.8-
αa36(1)182(9)41(6)
αb11.5(6)159(22)46(6)
αc26(1)172(7)47(4)
αα-73(9)-
αβ−3(1)97(12)-
αγ-−10(8)-
αV73(2)406(25)134(9)
1 At T = 120 °C; α—coefficient of thermal expansion (α11, α22, α33—eigenvalues (main values); αa, αb, αc—values along crystallographic axes); <α11a—angle between α11 and a.
Table
Table 12. Compounds with formulas XMgCl3·6H2O and (X)2FeCl5·H2O.
Table 12. Compounds with formulas XMgCl3·6H2O and (X)2FeCl5·H2O.
FormulaSymmetryCation X+Ionic Radii 1 of X+, ÅReference
XMgCl3·6H2O
CsMgCl3·6H2OMonoclinic C2/cCs1.81[64]
RbMgCl3·6H2OMonoclinic C2/cRb1.52[58]
NH4MgCl3·6H2OMonoclinic C2/cNH41.48[57], this work
KMgCl3·6H2OOrthorhombic PnnaK1.38[65]
LiMgCl3·7H2OTrigonal R3Li0.76[66]
(X)2FeCl5·H2O
Cs2FeCl5·H2OOrthorhombic CmcmCs1.81[67]
Rb2FeCl5·H2OOrthorhombic PnmaRb1.52[67]
(NH4)2FeCl5·H2OOrthorhombic PnmaNH41.48[63], this work
K2FeCl5·H2OOrthorhombic PnmaK1.38[68]
1 Effective ionic radii for CN = 6 by Shannon [69] and for NH4 by Sidey [70].

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Zolotarev, A.A., Jr.; Zhitova, E.S.; Krzhizhanovskaya, M.G.; Rassomakhin, M.A.; Shilovskikh, V.V.; Krivovichev, S.V. Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin. Minerals 2019, 9, 486. https://doi.org/10.3390/min9080486

AMA Style

Zolotarev AA Jr., Zhitova ES, Krzhizhanovskaya MG, Rassomakhin MA, Shilovskikh VV, Krivovichev SV. Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin. Minerals. 2019; 9(8):486. https://doi.org/10.3390/min9080486

Chicago/Turabian Style

Zolotarev, Andrey A., Jr., Elena S. Zhitova, Maria G. Krzhizhanovskaya, Mikhail A. Rassomakhin, Vladimir V. Shilovskikh, and Sergey V. Krivovichev. 2019. "Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin" Minerals 9, no. 8: 486. https://doi.org/10.3390/min9080486

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