inorganic compounds
Calcioferrite with composition (Ca3.94Sr0.06)Mg1.01(Fe2.93Al1.07)(PO4)6(OH)4·12H2O
aDepartment of Geosciences, University of Arizona, 1040 E. 4th Street, Tucson, AZ 85721-0077, USA
*Correspondence e-mail: barbaralafuente@email.arizona.edu
Calcioferrite, ideally Ca4MgFe3+4(PO4)6(OH)4·12H2O (tetracalcium magnesium tetrairon(III) hexakis-phosphate tetrahydroxide dodecahydrate), is a member of the calcioferrite group of hydrated calcium phosphate minerals with the general formula Ca4AB4(PO4)6(OH)4·12H2O, where A = Mg, Fe2+, Mn2+ and B = Al, Fe3+. Calcioferrite and the other three known members of the group, montgomeryite (A = Mg, B = Al), kingsmountite (A = Fe2+, B = Al), and zodacite (A = Mn2+, B = Fe3+), usually occur as very small crystals, making their structure refinements by conventional single-crystal X-ray diffraction challenging. This study presents the first of calcioferrite with composition (Ca3.94Sr0.06)Mg1.01(Fe2.93Al1.07)(PO4)6(OH)4·12H2O based on single-crystal X-ray diffraction data collected from a natural sample from the Moculta quarry in Angaston, Australia. Calcioferrite is isostructural with montgomeryite, the only member of the group with a reported structure. The calcioferrite structure is characterized by (Fe/Al)O6 octahedra (site symmetries 2 and -1) sharing corners (OH) to form chains running parallel to [101]. These chains are linked together by PO4 tetrahedra (site symmetries 2 and 1), forming [(Fe/Al)3(PO4)3(OH)2] layers stacking along [010], which are connected by (Ca/Sr)2+ cations (site symmetry 2) and Mg2+ cations (site symmetry 2; half-occupation). Hydrogen-bonding interactions involving the water molecules (one of which is equally disordered over two positions) and OH function are also present between these layers. The relatively weaker bonds between the layers account for the cleavage of the mineral parallel to (010).
CCDC reference: 988095
Related literature
For background references to calcioferrite, see: Blum (1858); Palache et al. (1951); Henderson & Peisley (1985). For discussions on minerals isostructural with calcioferrite, see: Larsen (1940); Moore & Araki (1974); Fanfani et al. (1976); Dunn et al. (1979, 1983, 1988). For information on phosphate minerals, see: Mead & Mrose (1968); Huminicki & Hawthorne (2002). For details of rigid-body thermal motion of atoms in crystals, see: Downs (2000).
Experimental
Crystal data
|
Data collection: APEX2 (Bruker, 2004); cell SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
CCDC reference: 988095
10.1107/S1600536814004061/wm5004sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536814004061/wm5004Isup2.hkl
Calcioferrite was originally described by Blum (1858) from a sample found in Battenberg (Rhenish, Bavaria) with the chemical composition (wt.%): P2O5 34.01, Fe2O3 24.34, Al2O3 2.90, CaO 14.81, MgO 2.65, and H2O 20.56 (total = 99.27). Larsen (1940) reported montgomeryite with an ideal chemical formula Ca4Al5(PO4)6(OH)5.11H2O without recognizing its relationship to calcioferrite. Palache et al. (1951), on the basis of the chemistry given by Blum (1858), proposed the chemical formula Ca3Fe3(PO4)4(OH)3.8H2O for calcioferrite. By comparing chemical compositions and X-ray powder diffraction profiles between calcioferrite and montgomeryite, Mead & Mrose (1968) suggested that these two minerals are isostructural. Moore & Araki (1974) first solved the structure of montgomeryite in
C2/c and revised its chemical formula to Ca4MgAl4(PO4)6(OH)4.12H2O. Nevertheless, Fanfani et al. (1976) observed the presence of some weak reflections that violate the C2/c symmetry for montgomeryite, leading them to propose C2 as the actual for this mineral. Dunn et al. (1983) studied red montgomeryite from the Tip Top Pegmatite and also concluded that calcioferrite is the Fe3+ analog of montgomeryite based on the similarity between their X-ray powder diffraction patterns. Consequently, they modified the ideal chemical formula of calcioferrite to its present form, Ca4MgFe3+4(PO4)6(OH)4.12H2O.A second locality for calcioferrite was reported by Henderson & Peisley (1985) at the Moculta quarry in Angaston, South Australia, associated with apatite, jarosite, cacoxenite and altered pyrite, the latter probably being the source of Fe3+. The chemistry and X-ray power data of calcioferrite from this locality are consistent with the previous observations that calcioferrite is isotypic with montgomeryite. However, the structure of calcioferrite has remained undetermined because of its small crystal size and generally poor crystallinity. In the course of identifying minerals for the RRUFF Project (http://rruff.info), we were able to isolate a single crystal of calcioferrite and determine its structure by means of single-crystal X-ray diffraction, demonstrating that its
is C2/c.The general composition of the calcioferrite group minerals can be expressed as Ca4AB4(PO4)6(OH)4.12H2O with A = Mg, Fe2+, Mn2+ and B = Al, Fe3+. In addition to calcioferrite, there are three other known members in the group, including montgomeryite (A = Mg, B = Al) (Moore & Araki, 1974; Fanfani et al., 1976), kingsmountite (A = Fe2+, B = Al) (Dunn et al., 1979), and zodacite (A = Mn2+, B = Fe3+) (Dunn et al., 1988). The structure of calcioferrite contains seven non-hydrogen cation sites, two for Ca [((Cal/Sr1); 1; occupancy ratio Fe:Al = 0.651:0.349) and (Fe2/Al2; 2; occupancy ratio Fe:Al = 0.814:0.186)], one for Mg [site symmetry 2; half-occupation], and two for P [(P1; 2) and P2 (site symmetry 1)]. The chains of corner-sharing (Fe/Al)O6 octahedra (parallel to [101]) are linked together by PO4 tetrahedra to form [(Fe/Al)3(PO4)3(OH)2] layers stacking along [010] (Figs. 1, 2). The configuration of such layers has been observed in many others (Fe/Al)3+ phosphates (Huminicki & Hawthorne, 2002). The [(Fe/Al)3(PO4)3(OH)2] layers are connected by Ca2+ cations (coordination numbers of eight) and Mg2+ cations (coordination number of six). The relatively weaker bonds between the layers account for the cleavage of the mineral parallel to (010).
2; occupancy ratio Ca:Sr =0.97:0.03) and Ca2 (site symmetry 2)], two for Fe [((Fe1/Al1);The (Fe/Al)O6 octahedral chains in calcioferrite have a repeat of ~7.1 Å, similar to those examined by Huminicki & Hawthorne (2002). Between the two distinct B sites, the B1 site is strongly preferred by Al. The average (Fe/Al)1—O distance is 1.962 Å, which is evidently shorter than the average (Fe/Al)2—O distance (1.997 Å). The analysis of the anisotropic displacement parameters of atoms indicates that PO4 tetrahedra behave as rigid bodies, as should be expected for such strongly bonded tetrahedral groups (Downs, 2000). Both (Ca/Sr)1 and Ca2 are eight-coordinated, with the former by (4 O + 4 H2O) and the latter by (6 O + 2 H2O). The (Ca/Sr)1O8 polyhedra are situated between the [(Fe/Al)3(PO4)3(OH)2] layers, whereas the Ca2O8 polyhedra are located within the layers (Fig. 2). Hydrogen-bonding interactions involving the water molecules and OH- function are also present between these layers (Table 1).
As observed for the (Ca/Sr)1O8 polyhedra, the MgO6 octahedra are also located between the [(Fe/Al)3(PO4)3(OH)2] layers (Fig. 2). The Mg-site is randomly half-occupied with an average Mg—O bond length of 1.988 Å. The water O atom OW3 appears to be split between two positions (OW3A and OW3B), representing the two sets of water molecules correlated to the occupancy of the Mg-site (Fig. 3). The displacement parameters for OW3A are significantly larger and elongated than those of OW3B, suggesting that OW3A correlates with the vacancy and therefore is in a "softer" potential well. Interatomic distances between Mg—OW3B are more similar to each other (2.145 (8) Å and 2.200 (9) Å) while those between Mg—OW3A are more dissimilar to each other (2.535 (11) Å and 2.117 (10) Å). This is consistent with our suggestion, based on displacement parameters, that OW3A is not bonded to Mg.
The calcioferrite specimen used in this study is from Moculta quarry, Angaston, Australia, and is in the collection of the RRUFF project (deposition R120092: http://rruff.info/R120092). Its chemical composition was determined with a CAMECA SX100 electron microprobe at the conditions of 15kV, 1nA and a beam size of 5µm. These conditions were optimized to minimize sample damage by the electron beam due to the small size of the sample (Fig. 4) and its high hydration. Ten analysis points yielded an average composition (wt. %): CaO 17.40 (41), SrO 0.57 (21), MgO 3.24 (16), Fe2O3 18.51(1.44), Al2O3 4.29 (86) and P2O5 34.97 (86), with H2O 21.02 calculated by difference. Due to the significant dehydration of the sample during the electron microprobe analysis, this composition may not be very accurate and was used only for the estimation of cation ratios. By assuming six P cations per formula, the relative ratio of (Ca, Sr):Mg:(Fe, Al):P is 3.85:0.98:3.85:6.00. The composition of the crystal is then (Ca3.94Sr0.06)Σ=4Mg(Fe2.93Al1.07)Σ=4(PO4)6(OH)4.12H2O as determined by the combination of the electron microprobe and the X-ray structural data.
All non-hydrogen atoms were refined with anisotropic displacement parameters. Only H atoms bonded to OW1, OW2, and OH could be located from difference Fourier syntheses and their positions refined with a fixed isotropic displacement parameter (Uiso = 0.03). The H atoms bonded to the disordered OW3 atom could not be located and were excluded from refinement.
The occupancies of Al and Fe of the two B sites were refined with their ratio determined from the electron microprobe analysis. The small amount of Sr detected from the electron microprobe analysis was assigned into the Ca1 site, because this site is significantly larger than the Ca2 site. The maximum residual electron density in the difference Fourier map, 0.57 e/Å3, was located at (0, 0.0340, 0.25), 0.69 Å from Sr1 and the minimum, -0.60 e/Å3, at (0.8637, 0.3318, 0.0082), 1.31 Å from OW1.
Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. A slice of the calcioferrite structure, showing the [(Fe/Al)3(PO4)3(OH)2] layer. Yellow octahedra, purple tetrahedra and red spheres represent (Fe/Al)O6, PO4 and OH groups, respectively. | |
Fig. 2. The [(Fe/Al)3(PO4)3(OH)2] layers are stacked along [010]. They are connected by H2O and cations Ca2+ and Mg2+. Yellow and green octahedra represent (Fe/Al)O6 and MgO6 groups, respectively. Purple tetrahedra represent PO4 groups. Grey, aquamarine, blue and red spheres represent Ca2+ cations, H2O molecules, H atoms and O atoms, respectively. | |
Fig. 3. The crystal structure of calcioferrite showing atoms with anisotropic displacement ellipsoids at the 99% probability level. Yellow, purple, green and grey ellipsoids represent (Fe/Al), P, Mg and Ca sites, respectively. Red and aquamarine ellipsoids represent O atoms and H2O groups, respectively. Small blue spheres represent H atoms. | |
Fig. 4. A backscattered electron image of calcioferrite crystals. |
Ca4MgFe4(PO4)6(OH)4·12H2O | F(000) = 1243 |
Mr = 1234.28 | Dx = 2.629 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 2019 reflections |
a = 10.1936 (8) Å | θ = 2.2–29.9° |
b = 24.1959 (18) Å | µ = 2.60 mm−1 |
c = 6.3218 (4) Å | T = 293 K |
β = 91.161 (4)° | Plate, pale yellow |
V = 1558.9 (2) Å3 | 0.09 × 0.08 × 0.05 mm |
Z = 2 |
Bruker APEXII CCD area-detector diffractometer | 2348 independent reflections |
Radiation source: fine-focus sealed tube | 1712 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.049 |
φ and ω scan | θmax = 30.5°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −14→14 |
Tmin = 0.800, Tmax = 0.881 | k = −34→34 |
10490 measured reflections | l = −8→8 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.039 | All H-atom parameters refined |
wR(F2) = 0.094 | w = 1/[σ2(Fo2) + (0.0509P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max = 0.002 |
2348 reflections | Δρmax = 0.57 e Å−3 |
160 parameters | Δρmin = −0.60 e Å−3 |
4 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0012 (3) |
Ca4MgFe4(PO4)6(OH)4·12H2O | V = 1558.9 (2) Å3 |
Mr = 1234.28 | Z = 2 |
Monoclinic, C2/c | Mo Kα radiation |
a = 10.1936 (8) Å | µ = 2.60 mm−1 |
b = 24.1959 (18) Å | T = 293 K |
c = 6.3218 (4) Å | 0.09 × 0.08 × 0.05 mm |
β = 91.161 (4)° |
Bruker APEXII CCD area-detector diffractometer | 2348 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | 1712 reflections with I > 2σ(I) |
Tmin = 0.800, Tmax = 0.881 | Rint = 0.049 |
10490 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 4 restraints |
wR(F2) = 0.094 | All H-atom parameters refined |
S = 1.01 | Δρmax = 0.57 e Å−3 |
2348 reflections | Δρmin = −0.60 e Å−3 |
160 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Ca1 | 0.0000 | 0.06262 (3) | 0.2500 | 0.0138 (2) | 0.9700 (1) |
Sr1 | 0.0000 | 0.06262 (3) | 0.2500 | 0.0138 (2) | 0.0300 (1) |
Ca2 | 0.0000 | 0.33191 (4) | 0.2500 | 0.0155 (2) | |
Mg | 0.0000 | 0.47193 (12) | 0.2500 | 0.0130 (6) | 0.5050 (1) |
Fe1 | 0.2500 | 0.2500 | 0.0000 | 0.0076 (2) | 0.651 (3) |
Al1 | 0.2500 | 0.2500 | 0.0000 | 0.0076 (2) | 0.349 (3) |
Fe2 | 0.0000 | 0.16865 (3) | −0.2500 | 0.00762 (17) | 0.814 (3) |
Al2 | 0.0000 | 0.16865 (3) | −0.2500 | 0.00762 (17) | 0.186 (3) |
P1 | 0.5000 | 0.30208 (5) | −0.2500 | 0.0115 (2) | |
P2 | 0.26354 (8) | 0.11351 (3) | 0.96145 (13) | 0.01383 (19) | |
O1 | 0.6135 (2) | 0.26286 (10) | 0.7074 (4) | 0.0198 (5) | |
O2 | 0.4700 (2) | 0.34019 (9) | 0.5625 (3) | 0.0164 (5) | |
O3 | 0.3130 (2) | 0.17285 (9) | 0.0051 (4) | 0.0189 (5) | |
O4 | 0.3782 (2) | 0.08573 (9) | 0.8546 (4) | 0.0201 (5) | |
O5 | 0.1438 (2) | 0.11435 (9) | 0.8055 (4) | 0.0192 (5) | |
O6 | 0.2234 (3) | 0.08585 (10) | 0.1650 (4) | 0.0284 (6) | |
OH | 0.3675 (2) | 0.27149 (10) | 0.2343 (4) | 0.0173 (5) | |
OW1 | 0.1598 (3) | 0.32890 (13) | 0.5225 (4) | 0.0314 (7) | |
OW2 | 0.1120 (2) | 0.02555 (10) | 0.5770 (4) | 0.0229 (5) | |
OW3A | 0.1164 (9) | 0.4665 (4) | 0.6075 (13) | 0.0281 (17) | 0.50 |
OW3B | 0.1193 (8) | 0.4792 (3) | 0.5320 (12) | 0.0199 (15) | 0.50 |
H11 | 0.178 (4) | 0.3424 (18) | 0.620 (6) | 0.030* | |
H12 | 0.213 (4) | 0.3114 (17) | 0.483 (7) | 0.030* | |
H21 | 0.123 (4) | 0.0581 (17) | 0.673 (6) | 0.030* | |
H22 | 0.191 (4) | 0.0156 (17) | 0.553 (6) | 0.030* | |
H1 | 0.372 (4) | 0.2496 (18) | 0.303 (7) | 0.030* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ca1 | 0.0177 (4) | 0.0103 (4) | 0.0132 (4) | 0.000 | −0.0008 (3) | 0.000 |
Sr1 | 0.0177 (4) | 0.0103 (4) | 0.0132 (4) | 0.000 | −0.0008 (3) | 0.000 |
Ca2 | 0.0149 (4) | 0.0155 (5) | 0.0160 (5) | 0.000 | 0.0010 (3) | 0.000 |
Mg | 0.0115 (14) | 0.0084 (14) | 0.0192 (16) | 0.000 | 0.0000 (11) | 0.000 |
Fe1 | 0.0081 (4) | 0.0043 (3) | 0.0104 (4) | −0.0008 (3) | 0.0006 (2) | −0.0003 (3) |
Al1 | 0.0081 (4) | 0.0043 (3) | 0.0104 (4) | −0.0008 (3) | 0.0006 (2) | −0.0003 (3) |
Fe2 | 0.0088 (3) | 0.0055 (3) | 0.0087 (3) | 0.000 | 0.0011 (2) | 0.000 |
Al2 | 0.0088 (3) | 0.0055 (3) | 0.0087 (3) | 0.000 | 0.0011 (2) | 0.000 |
P1 | 0.0129 (5) | 0.0102 (5) | 0.0113 (5) | 0.000 | 0.0019 (4) | 0.000 |
P2 | 0.0160 (4) | 0.0093 (4) | 0.0164 (4) | 0.0018 (3) | 0.0049 (3) | 0.0028 (3) |
O1 | 0.0223 (12) | 0.0176 (12) | 0.0198 (12) | 0.0062 (9) | 0.0083 (9) | 0.0031 (9) |
O2 | 0.0220 (12) | 0.0147 (11) | 0.0127 (11) | 0.0020 (9) | 0.0022 (8) | 0.0001 (8) |
O3 | 0.0204 (12) | 0.0129 (11) | 0.0233 (13) | 0.0027 (9) | −0.0031 (9) | −0.0033 (9) |
O4 | 0.0196 (12) | 0.0152 (12) | 0.0258 (13) | 0.0056 (9) | 0.0068 (9) | 0.0019 (9) |
O5 | 0.0160 (12) | 0.0132 (12) | 0.0282 (13) | 0.0031 (9) | −0.0034 (9) | −0.0036 (10) |
O6 | 0.0324 (14) | 0.0273 (15) | 0.0261 (14) | 0.0048 (11) | 0.0138 (11) | 0.0118 (11) |
OH | 0.0197 (12) | 0.0115 (12) | 0.0206 (13) | −0.0040 (9) | −0.0034 (9) | 0.0048 (9) |
OW1 | 0.0299 (16) | 0.0415 (19) | 0.0226 (15) | −0.0034 (13) | −0.0055 (11) | 0.0040 (13) |
OW2 | 0.0221 (13) | 0.0194 (13) | 0.0271 (14) | −0.0027 (11) | −0.0022 (10) | −0.0048 (10) |
OW3A | 0.040 (4) | 0.018 (4) | 0.026 (5) | 0.009 (3) | −0.006 (4) | −0.005 (3) |
OW3B | 0.018 (3) | 0.015 (4) | 0.026 (5) | 0.005 (2) | −0.008 (3) | 0.000 (3) |
Ca1—O6i | 2.417 (2) | Mg—OW3Bviii | 2.200 (9) |
Ca1—O6 | 2.417 (2) | Mg—OW3Ai | 2.535 (8) |
Ca1—OW2i | 2.507 (3) | Mg—OW3A | 2.535 (8) |
Ca1—OW2 | 2.507 (3) | Fe1—O1iii | 1.956 (2) |
Ca1—O2ii | 2.648 (2) | Fe1—O1x | 1.956 (2) |
Ca1—O2iii | 2.648 (2) | Fe1—OHvii | 1.956 (2) |
Ca1—OW2iv | 2.665 (3) | Fe1—OH | 1.956 (2) |
Ca1—OW2v | 2.665 (3) | Fe1—O3 | 1.974 (2) |
Ca2—OW1i | 2.348 (3) | Fe1—O3vii | 1.974 (2) |
Ca2—OW1 | 2.348 (3) | Fe2—OHvii | 1.981 (2) |
Ca2—O4ii | 2.446 (2) | Fe2—OHiii | 1.981 (2) |
Ca2—O4iii | 2.446 (2) | Fe2—O5i | 1.995 (2) |
Ca2—O3vi | 2.524 (2) | Fe2—O5xi | 1.995 (2) |
Ca2—O3vii | 2.524 (2) | Fe2—O2vii | 2.016 (2) |
Ca2—O1ii | 2.585 (3) | Fe2—O2iii | 2.016 (2) |
Ca2—O1iii | 2.585 (3) | P1—O1x | 1.525 (2) |
Mg—O4iii | 1.990 (3) | P1—O1xi | 1.525 (2) |
Mg—O4ii | 1.990 (3) | P1—O2x | 1.528 (2) |
Mg—OW3Aviii | 2.117 (10) | P1—O2xi | 1.528 (2) |
Mg—OW3Aix | 2.117 (10) | P2—O6xii | 1.514 (2) |
Mg—OW3Bi | 2.145 (8) | P2—O4 | 1.519 (2) |
Mg—OW3B | 2.145 (8) | P2—O3xii | 1.545 (2) |
Mg—OW3Bix | 2.200 (9) | P2—O5 | 1.553 (2) |
O4iii—Mg—O4ii | 90.93 (18) | O1iii—Fe1—OHvii | 91.85 (10) |
O4iii—Mg—OW3Aviii | 173.6 (2) | O1x—Fe1—OHvii | 88.15 (10) |
O4ii—Mg—OW3Aviii | 89.6 (2) | OHvii—Fe1—OH | 180.00 (13) |
OW3Aviii—Mg—OW3Aix | 90.5 (5) | O1iii—Fe1—O3 | 94.26 (10) |
O4iii—Mg—OW3Bi | 89.3 (3) | O1x—Fe1—O3 | 85.74 (10) |
O4ii—Mg—OW3Bi | 97.4 (2) | OHvii—Fe1—O3 | 87.43 (10) |
OW3Aviii—Mg—OW3Bi | 84.3 (4) | OH—Fe1—O3 | 92.57 (10) |
OW3Aix—Mg—OW3Bi | 89.0 (2) | O3—Fe1—O3vii | 180.0 |
OW3Bi—Mg—OW3B | 170.5 (5) | OHvii—Fe2—OHiii | 86.06 (14) |
O4iii—Mg—OW3Bix | 79.2 (2) | OHvii—Fe2—O5i | 171.18 (9) |
O4ii—Mg—OW3Bix | 160.24 (19) | OHiii—Fe2—O5i | 88.56 (10) |
OW3Aviii—Mg—OW3Bix | 102.1 (3) | O5i—Fe2—O5xi | 97.60 (13) |
OW3Aix—Mg—OW3Bix | 15.01 (19) | OHvii—Fe2—O2vii | 90.57 (9) |
OW3Bi—Mg—OW3Bix | 99.5 (3) | OHiii—Fe2—O2vii | 98.35 (9) |
OW3B—Mg—OW3Bix | 75.3 (3) | O5xi—Fe2—O2vii | 88.68 (9) |
OW3Bix—Mg—OW3Bviii | 115.1 (4) | O2vii—Fe2—O2iii | 167.81 (13) |
O4iii—Mg—OW3Ai | 88.6 (2) | O1x—P1—O1xi | 103.03 (19) |
O4ii—Mg—OW3Ai | 87.2 (2) | O1x—P1—O2x | 112.29 (12) |
OW3Aviii—Mg—OW3Ai | 85.0 (3) | O1xi—P1—O2x | 111.83 (13) |
OW3Aix—Mg—OW3Ai | 99.2 (4) | O2x—P1—O2xi | 105.75 (18) |
OW3Bi—Mg—OW3Ai | 10.2 (3) | O6xii—P2—O4 | 113.94 (14) |
OW3B—Mg—OW3Ai | 173.1 (4) | O6xii—P2—O3xii | 110.61 (14) |
OW3Bix—Mg—OW3Ai | 109.38 (17) | O4—P2—O3xii | 103.84 (13) |
OW3Bviii—Mg—OW3Ai | 74.0 (3) | O6xii—P2—O5 | 108.83 (14) |
OW3Ai—Mg—OW3A | 174.1 (4) | O4—P2—O5 | 109.00 (13) |
O1iii—Fe1—O1x | 180.0 | O3xii—P2—O5 | 110.54 (13) |
Symmetry codes: (i) −x, y, −z+1/2; (ii) −x+1/2, −y+1/2, −z+1; (iii) x−1/2, −y+1/2, z−1/2; (iv) −x, −y, −z+1; (v) x, −y, z−1/2; (vi) x−1/2, −y+1/2, z+1/2; (vii) −x+1/2, −y+1/2, −z; (viii) x, −y+1, z−1/2; (ix) −x, −y+1, −z+1; (x) −x+1, y, −z+1/2; (xi) x, y, z−1; (xii) x, y, z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
OW1—H11···O3ii | 0.72 (3) | 2.40 (4) | 2.994 (4) | 142 (5) |
OW1—H11···O6ii | 0.72 (3) | 2.41 (3) | 3.079 (4) | 155 (5) |
OW1—H12···OH | 0.74 (3) | 2.45 (3) | 3.145 (4) | 159 (4) |
OW1—H12···O2 | 0.74 (3) | 2.75 (4) | 3.179 (4) | 120 (4) |
OW2—H21···O5 | 1.00 (4) | 1.61 (4) | 2.606 (3) | 174 (4) |
OW2—H22···OW3Bii | 0.86 (4) | 2.02 (4) | 2.841 (9) | 160 (4) |
OW2—H22···OW3Aii | 0.86 (4) | 2.27 (4) | 3.033 (10) | 148 (4) |
OW2—H22···O6xiii | 0.86 (4) | 2.57 (4) | 2.973 (4) | 109 (3) |
OH—H1···OW1ii | 0.69 (4) | 2.22 (4) | 2.891 (4) | 165 (5) |
Symmetry codes: (ii) −x+1/2, −y+1/2, −z+1; (xiii) x, −y, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
OW1—H11···O3i | 0.72 (3) | 2.40 (4) | 2.994 (4) | 142 (5) |
OW1—H11···O6i | 0.72 (3) | 2.41 (3) | 3.079 (4) | 155 (5) |
OW1—H12···OH | 0.74 (3) | 2.45 (3) | 3.145 (4) | 159 (4) |
OW1—H12···O2 | 0.74 (3) | 2.75 (4) | 3.179 (4) | 120 (4) |
OW2—H21···O5 | 1.00 (4) | 1.61 (4) | 2.606 (3) | 174 (4) |
OW2—H22···OW3Bi | 0.86 (4) | 2.02 (4) | 2.841 (9) | 160 (4) |
OW2—H22···OW3Ai | 0.86 (4) | 2.27 (4) | 3.033 (10) | 148 (4) |
OW2—H22···O6ii | 0.86 (4) | 2.57 (4) | 2.973 (4) | 109 (3) |
OH—H1···OW1i | 0.69 (4) | 2.22 (4) | 2.891 (4) | 165 (5) |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) x, −y, z+1/2. |
Acknowledgements
We gratefully acknowledge support for this study by the Arizona Science Foundation and NASA NNX11AP82A, Mars Science Laboratory Investigations. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Aeronautics and Space Administration.
References
Blum, J. R. (1858). Neues Jahrb. Miner. Geog. Geol. Petrefaktenkunde, pp. 287–293. Google Scholar
Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Downs, R. T. (2000). Rev. Mineral. Geochem. 41, 61–88. CrossRef Google Scholar
Downs, R. T. & Hall-Wallace, M. (2003). Am. Mineral. 88, 247–250. CAS Google Scholar
Dunn, P. J., Grice, J. D. & Metropolis, W. C. (1988). Am. Mineral. 73, 1179–1181. CAS Google Scholar
Dunn, P. J., Peacor, D. R., White, J. S. & Ramik, R. A. (1979). Can. Mineral. 17, 579–582. CAS Google Scholar
Dunn, P. J., Roberts, W. L., Campbell, T. J. & Leavens, P. B. (1983). Miner. Rec. 14, 195–197. CAS Google Scholar
Fanfani, L., Nunzi, A., Zanazzi, P. F. & Zanzari, A. R. (1976). Am. Mineral. 61, 12–14. CAS Google Scholar
Henderson, W. A. & Peisley, V. (1985). Miner. Rec. 16, 477–480. CAS Google Scholar
Huminicki, D. M. C. & Hawthorne, F. C. (2002). Rev. Mineral. Geochem. 48, 123–253. Web of Science CrossRef CAS Google Scholar
Larsen, E. S. (1940). Am. Mineral. 25, 315–326. CAS Google Scholar
Mead, C. W. & Mrose, M. E. (1968). Geol. Surv. Prof. Pap. 600–D, 204–206. Google Scholar
Moore, P. B. & Araki, T. (1974). Am. Mineral. 59, 843–850. CAS Google Scholar
Palache, C., Berman, H. & Frondel, C. (1951). The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837–1892, Volume II, 7th ed., pp. 976–977. New York: John Wiley and Sons, Inc. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.