The crystal structure of bavenite

Kharitonov, Yu. A.; Kuzmin, A.; Ilyukhin, V. V.; Belov, N. V.

doi:10.1007/bf00744541

Cited by 6 publications

(17 citation statements)

References 3 publications

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“…Detailed chemical compositions were given by Switzer and Reichen (1960), Berry (1963), Beus (1966) and Cannillo et al (1966), and both Cannillo et al (1966) and Kharitonov et al (1971) showed that the crystal structure is a framework of silicate and beryllate tetrahedra with the general formula Ca 4 [Be (2 + x) Al (2-x) ][Si 9 O (26-x) (OH) (2 + x) ]. Beus (1966) .…”

Section: Introductionmentioning

confidence: 99%

“…BAVENITE is a calcium beryllium aluminosilicate mineral occurring primarily in granitic pegmatites (Černý, 2002) and is a widespread product of hydrothermal alteration, particularly of beryl (Černý, 1968;Bondi et al, 1983). Detailed chemical compositions were given by Switzer and Reichen (1960), Berry (1963), Beus (1966) and Cannillo et al (1966), and both Cannillo et al (1966) and Kharitonov et al (1971) showed that the crystal structure is a framework of silicate and beryllate tetrahedra with the general formula Ca 4 [Be (2 + x) Al (2-x) ][Si 9 O (26-x) (OH) (2 + x) ]. Beus (1966) wrote the bavenite series as between the compositions Ca 4 Be 2 Al 2 Si 9 O 26 (OH) 2 and Ca 4 Be 3 AlSi 9 O 25 (OH) 3 .…”

Section: Introductionmentioning

confidence: 99%

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Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

et al. 2017

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Bohseite is an orthorhombic calcium beryllium aluminosilicate with variable Al content and an endmember formula Ca 4 Be 4 Si 9 O 24 (OH) 4 , that was discovered in the Piława Górna quarry in the eastern part of the Góry Sowie Block, ∼50 km southwest of Wrocław, SW Poland. It occurs in a zoned anatectic pegmatite dyke in close association with microcline, Cs-rich beryl, phenakite, helvite, 'lepidolite', probably bertrandite and unidentified Be-containing mica as alteration products after a primary Be mineral, probably beryl. Bohseite forms fan-like or parallel aggregates (up to 0.7 cm) of white, platy crystals (up to 2 mm long) with characteristic striations. It is white with a white streak, is translucent and has a vitreous lustre; it does not fluoresce under ultraviolet light. The cleavage is perfect on {001} and fair on {010}, and neither parting nor twinning was observed. Bohseite is brittle with a splintery fracture and Mohs hardness is 5-6. The calculated density is 2.719 g cm -3 . The indices of refraction are α = 1.579, β = 1.580, γ = 1.597, all ±0.002; 2Vobs = 24(3)°, 2Vcalc = 27°; the optic orientation is as follows: X^a = 16.1°, Y^b = 16.1°, Z // c. Bohseite shows orthorhombic diffraction symmetry, space group Cmcm, a = 23.204(6), b = 4.9442(9), c = 19.418(6) Å, V = 2227.7(4) Å 3 , Z = 4. The crystal structure was refined to an R 1 value of 2.17% based on single-crystal data, and the chemical composition was determined by electron-microprobe analysis. Bohseite is isostructural with bavenite. Bohseite was originally approved with an end-member composition of Ca 4 Be 3 AlSi 9 O 25 (OH) 3 , but subsequent discovery of compositions with Be > 3.0 apfu led to redefinition of its end-member composition, holotype sample and locality, as reported here. There is extensive solid solution in bavenite-bohseite according to the scheme O(2) OH -+

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

et al. 2017

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“…The data of previous works (KHARITONOV et al 1969, 1970 reveal that Na2Cr,0,. 2 H,O structure is formed of octahedra and tetrahedra.…”

Section: Results Of Epr Study and Discussionmentioning

confidence: 87%

EPR spectra of irradiated Na₂Cr₂O₇ · 2 H₂O crystals

Alybakov¹,

Gubanova²,

Tojchiev³

1980

Cryst Res and Technol

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The EPR spectra of X-irradiated Na,Cr,O, . 2 H,O crystals grown from the aqueous solution at room temperature are studied. Three groups of lines are detected, which marked conventionally as C,, C, and C,. Each of the C, and C, line groups is a superposition of two doublets. The lines are interpreted as due to the Cr5+ ions in the distorted (stretched) oxygenous tetrahedron. The doublet structure is due to hyperfine interaction with nuclei of 1/2 spin which are protons of water. It is shown that the C, and C, line groups are due to the centers of the same type with different orientations in the lattice. The principal gtensor values for these centres were as follows: gz = 1.916, g , = 1.978, gz = 1.986.

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“…Neither e. s. d.'s nor anisotropic displacement parameters were given by Kharitonov et al [16] in the paper on the Na 2 Cr 2 O 7 · 2H 2 O structure and the R value was reported to be 0.083, based on film data. Here we present a redetermination of the Na 2 Cr 2 O 7 · 2H 2 O structure where the hydrogen atoms have been located and the absolute structure has been established.…”

Section: Structural Description Of Na 2 Cr 2 O 7 · 2h 2 O (5)mentioning

confidence: 94%

“…One crystal structure of ammonium dichromate has been published [7,13]. Sporadic cases of hydrated dichromates have been structurally characterized until now: the sodium dichromate tetrahydrate [14], three modifications of lithium dichromate dihydrate [15] and the sodium dichromate dihydrate [16]. Only three structures with pyrosulfate anions were known [17] until recently when Ståhl et al [18] There is evidence for the existence of a "chromo sulfate" anion [19], but no structures of compounds containing CrSO 7 2− ions have been reported until now.…”

Section: Introductionmentioning

confidence: 99%

Synthesis Methods For Ce(CrO₄)₂ · χH₂O And Crystal Structures Of K₂CrSO₇, (NH₄)₂Cr₂O₇ And Na₂Cr₂O₇ · 2H₂O

Casari

Eriksson

Langer

2007

Zeitschrift Für Naturforschung B

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New and quick methods to synthesize Ce(CrO 4 ) 2 · 2H 2 O and Ce(CrO 4 ) 2 · H 2 O, giving high yields, are described. The methods are based on exchange reactions by refluxing in water or on solid state reactions. The first crystal structure containing a chromatosulfato ion is presented. K 2 CrSO 7 belongs to space group P2 1 /n with a = 7.4024(1), b = 7.3908(1), c = 12.9883(2)Å, β = 90.021(1) • and Z = 4. The CrSO 7 2− ion, consisting of one chromate group sharing one oxygen atom with one sulfate group, has a pseudo syn-C 2v conformation with eclipsed oxygen atoms. K 2 CrSO 7 forms a three dimensional network of CrSO 7 2− ions held together by the charge balancing potassium ions, with the general structural features common with dichromate-like structures. The redetermination of the structures of (NH 4 ) 2 Cr 2 O 7 (space group C2/c, with hydrogen atoms located) and Na 2 Cr 2 O 7 · 2H 2 O (space group P2 1 , with hydrogen atoms located and the absolute structure established) are reported.

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The crystal structure of bavenite

Cited by 6 publications

References 3 publications

Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

EPR spectra of irradiated Na₂Cr₂O₇ · 2 H₂O crystals

Synthesis Methods For Ce(CrO₄)₂ · χH₂O And Crystal Structures Of K₂CrSO₇, (NH₄)₂Cr₂O₇ And Na₂Cr₂O₇ · 2H₂O

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The crystal structure of bavenite

Cited by 6 publications

References 3 publications

Bohseite, ideally Ca4Be4Si9O24(OH4, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

Bohseite, ideally Ca4Be4Si9O24(OH4, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

EPR spectra of irradiated Na2Cr2O7 · 2 H2O crystals

Synthesis Methods For Ce(CrO4)2 · χH2O And Crystal Structures Of K2CrSO7, (NH4)2Cr2O7 And Na2Cr2O7 · 2H2O

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Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

Bohseite, ideally Ca₄Be₄Si₉O₂₄(OH₄, from the Piława Górna quarry, the Góry Sowie Block, SW Poland

EPR spectra of irradiated Na₂Cr₂O₇ · 2 H₂O crystals

Synthesis Methods For Ce(CrO₄)₂ · χH₂O And Crystal Structures Of K₂CrSO₇, (NH₄)₂Cr₂O₇ And Na₂Cr₂O₇ · 2H₂O