Abstract
In order to characterize the role of Ti in the crystal structure of calcium amphiboles with high or even dominant oxo-component, the crystal structure of a Ti-rich calcium amphibole from a gabbro at Kaersut, Greenland, has been refined with single-crystal MoKα X-ray intensity data to an R 1(F) index of ~0.025, and with single-crystal Laue neutron intensity data to an R 1(F) index of ~0.053. The crystal used for X-ray structure refinement was characterized by electron- and ion-microprobe analysis. The site populations of the C-group cations Mg, Fe and Ti were calculated from the refined site-scattering values for the M(1), M(2) and M(3) sites derived by both X-ray and neutron diffraction. Ti is distributed among all the three sixfold coordinated M sites, with a strong preference for the M(1) and M(3) sites, where its main role is maintaining electroneutrality at the deprotonated O(3) site. The pattern of distortion of the M(1), M(2) and M(3) octahedra differs from that in F-free deprotonated or partly deprotonated amphiboles, where Ti4+ does not occur at the M(3) site. The neutron structure refinement provides also a clear picture of the environment of the proton, anisotropic displacement behaviour and potential hydrogen-bonding arrangements. A trifurcated hydrogen-bonding configuration has been identified, with two O(6) and one O(7) oxygen atoms as acceptors of weak hydrogen-bonds.
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References
Brown ID (1981) The bond-valence method: an empirical approach to chemical structure and bonding. In: O’Keeffe M, Navrotsky A (eds) Structure and bonding in crystals, vol 2. Academic Press, New York, pp 1–30
Brown ID (2002) The chemical bond in inorganic chemistry. The bond valence model. Oxford University Press, Oxford
Brown ID, Shannon RD (1973) Empirical bond strength–bond lengths curves for oxides. Acta Crystallogr A 29:266–282
Busing WR, Levy HA (1964) The effect of thermal motion on the estimation of bond lengths from diffraction measurements. Acta Crystallogr 17:142–146
Busing WR, Martin KO, Levy HA (1962) ORFLS. Report ORNL-Tm-305.- Oak Ridge Natl. Lab. Oak Ridge, Tn
Campbell JW (1995) LAUEGEN, an X-windows-based program for the processing of Laue diffraction data. J Appl Crystallogr 28:228–236
Campbell JW, Hao Q, Harding MM, Nguti ND, Wilkinson C (1998) LAUEGEN version 6.0 and INTLDM. J Appl Crystallogr 31:496–502
Cannillo E, Germani G, Mazzi F (1983) New crystallographic software for Philips PW11000 single crystal diffractometer. CNR Centro di Studio per la Cristallografia, Internal Report 2
Della Ventura G, Robert JL, Bény JM (1991) Tetrahedrally coordinated Ti4+ in synthetic Ti-rich potassic richterites: evidence from XRD, FTIR and Raman study. Am Mineral 76:1134–1140
Della Ventura G, Robert JL, Bény JM, Raudsepp M, Hawthorne FC (1993) The OH-F substitution in Ti-rich potassium-richterites: Rietveld structure refinement and FTIR and micro-Raman spectroscopic studies of synthetic amphiboles in the system K2O–Na2O–CaO–MgO–SiO2–TiO2–H2O–HF. Am Mineral 78:980–987
Della Ventura G, Robert JL, Hawthorne FC, Prost R (1996) Short-range disorder of Si and Ti in the tetrahedral double-chain unit of synthetic Ti-bearing potassium-richterite. Am Mineral 81:56–60
Della Ventura G, Oberti R, Hawthorne FC, Bellatreccia F (2007) FTIR spectroscopy of Ti-rich pargasites from Lherz and the detection of O2B at the anionic O3 site in amphiboles. Am Mineral 92:1645–1651
Edwards AJ (2011) Neutron diffraction: recent applications to chemical structure determination. Austral J Chem 64:869–872
Gatta GD, McIntyre GJ, Sassi R, Rotiroti N, Pavese A (2011) Hydrogen-bond and cation partitioning in 2M 1-muscovite: a single-crystal neutron-diffraction study at 295 and 20 K. Am Mineral 96:34–41
Gatta GD, McIntyre GJ, Bromiley G, Guastoni A, Nestola F (2012) A single-crystal neutron diffraction study of hambergite, Be2BO3(OH, F). Am Mineral 97:1891–1897
Gatta GD, Merlini M, Valdrè G, Liermann H-P, Nénert G, Rothkirch A, Kahlenberg V, Pavese A (2013) On the crystal structure and compressional behaviour of talc: a mineral of interest in petrology and material science. Phys Chem Miner 40:145–156
Gatta GD, Nénert G, Guastella G, Lotti P, Guastoni A, Rizzato S (2014) A single-crystal neutron and X-ray diffraction study of a Li, Be-bearing brittle mica. Min Mag 78:55–72
Hawthorne FC (1983) Quantitative characterization of site occupancies in minerals. Am Mineral 68:287–306
Hawthorne FC (1997) Short-range order in amphiboles: a bond-valence approach. Can Mineral 35:201–216
Hawthorne FC, Oberti R (2007) Amphiboles: crystal chemistry. Rev Miner Geochem 67:1–54
Hawthorne FC, Ungaretti L, Oberti R (1995) Site populations in minerals: terminology and presentation of results of crystal-structure refinement. Can Mineral 33:907–911
Hawthorne FC, Oberti R, Zanetti A, Czamanske GK (1998) The role of Ti in hydrogen-deficient amphiboles: sodic-calcic and sodic amphiboles from Coyote Peak, California. Can Mineral 36:1253–1265
Hawthorne FC, Cooper MA, Grice JD, Ottolini L (2000) A new anhydrous amphibole from the Eifel region, Germany: description and crystal structure of obertiite, NaNa2(Mg3Fe3+Ti4+)Si8O22O2. Am Mineral 85:236–241
Hawthorne FC, Oberti R, Harlow GE, Maresch W, Martin RF, Schumacher JC, Welch MD (2012) Nomenclature of the amphibole super-group. Am Mineral 97:2031–2048
Kitamura M, Tokonami M, Morimoto N (1975) Distribution of Ti in oxy-kaersutite. Contr Mineral Petrol 51:167–172
Konzett J (1997) Phase relations and chemistry of Ti-rich K-richterite-bearing mantle assemblages: an experimental study to 8 GPa in a Ti-KNCMASH system. Contrib Miner Petrol 128:385–404
Konzett J, Sweeney RJ, Thompson AB, Ulmer P (1997) Potassium amphibole stability in the upper mantle: an experimental study in a peralkaline KNCMASH system to 8.5 GPa. J Petrol 38:537–568
Larson AC (1967) Inclusion of secondary extinction in least-squares calculations. Acta Crystallogr 23:664–665
Leake BE (1968) A catalog of analysed calciferous and subcalciferous amphiboles together with their nomenclature and associated minerals. Geol Soc Am Spec Paper 98:210p
McIntyre GJ, Lemée-Cailleau MH, Wilkinson C (2006) High-speed neutron Laue diffraction comes of age. Phys B 385–386:1055–1058
Oberti R, Ungaretti L, Cannillo E, Hawthorne FC (1992) The behaviour of Ti in amphiboles: I. Four- and six-coordinated Ti in richterite. Eur J Mineral 4:425–439
Oberti R, Hawthorne FC, Cannillo E, Cámara F (2007) Long-range order in amphiboles. Rev Miner Geochem 67:125–171
Oberti R, Boiocchi M, Zema M, Della Ventura G (2016) Synthetic potassic-ferro-richterite: 1. Composition, crystal structure refinement and HT behavior by in operando single-crystal X-ray diffraction. Can Mineral (in press)
Ottolini L, Hawthorne FC (2001) SIMS ionization of hydrogen in silicates: a case study of kornerupine. J Anal At Spectrom 16:1266–1270
Ottolini L, Bottazzi P, Vannucci R (1993) Quantification of Li, Be and B in silicates by secondary ion mass spectrometry using conventional energy filtering. Anal Chem 65:1960–1968
Pechar F, Fuess H, Joswig W (1989) Refinement of the crystal structure of kaersutite (Vlcíhora, Bohemia) from neutron diffraction. Neues Jahrb Mineral Monat 89:137–143
Piltz RO (2011) Accurate data analysis for the Koala and VIVALDI neutron Laue diffractometers. Abstracts of the XXII IUCr Congress, Madrid (Spain) 22-30 August 2011. Acta Crystallogr A67:C155
Saxena SK, Ekström TK (1970) Statistical chemistry of calcic amphibole. Contrib Miner Petrol 26:276–284
Sears VF (1986) Neutron scattering lengths and cross-sections. In: Sköld K, Price DL (eds) Neutron scattering, methods of experimental physics, vol 23A. Academic Press, New York, pp 521–550
Sheldrick GM (2008) A short history of SHELX. Acta Crystallogr A 64:112–122
Tiepolo M, Zanetti A, Oberti R (1999) Detection, crystal-chemical mechanisms and petrological implications of [6]Ti4+ partitioning in pargasite and kaersutite. Eur J Mineral 11:345–354
Wilkinson C, Khamis HW, Stansfield RFD, McIntyre GJ (1988) Integration of single-crystal reflections using area multidetectors. J Appl Crystallogr 21:471–478
Wilshire HG, Meyer CE, Nakata JK, Calk LC, Shervais JW, Nielson JE, Schwarzman EC (1988) Mafic and ultramafic xenoliths from volcanic rocks of the Western United States. U.S. Geological Survey Professional Paper, 1443, pp 179
Acknowledgments
The authors thank the Bragg Institute, Australian Nuclear Science and Technology Organization, for the allocation of neutron beam time. Financial support for FCH was provided by a Canada Research Chair in Crystallography and Mineralogy, Discovery Grants from the Natural Sciences and Engineering Research Council of Canada and by Canada Foundation for Innovation Grants. Two anonymous reviewers are thanked for the constructive suggestions.
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Diego Gatta, G., McIntyre, G.J., Oberti, R. et al. Order of [6]Ti4+ in a Ti-rich calcium amphibole from Kaersut, Greenland: a combined X-ray and neutron diffraction study. Phys Chem Minerals 44, 83–94 (2017). https://doi.org/10.1007/s00269-016-0839-0
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DOI: https://doi.org/10.1007/s00269-016-0839-0