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Weissite from Gambatesa mine, Val Graveglia, Liguria, Italy: occurrence, composition and determination of the crystal structure

Published online by Cambridge University Press:  05 July 2018

L. Bindi ,
C. Carbone ,
D. Belmonte ,
R. Cabella  and
R. Bracco
L. Bindi*
Affiliation:
Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira 4, I-50121 Florence, Italy CNR – Istituto di Geoscienze e Georisorse, Sezione di Firenze, Via G. La Pira 4, I-50121 Florence, Italy
C. Carbone
Affiliation:
Dipartimento di Scienze della Terra, dell’Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, I-16132 Genoa, Italy
D. Belmonte
Affiliation:
Dipartimento di Scienze della Terra, dell’Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, I-16132 Genoa, Italy
R. Cabella
Affiliation:
Dipartimento di Scienze della Terra, dell’Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, I-16132 Genoa, Italy
R. Bracco
Affiliation:
Via Montenotte 18, I-17100 Savona, Italy
*
* E-mail: luca.bindi@unifi.it
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Abstract

Weissite, Cu2–xTe (x ≈ 0.21), a very rare copper telluride, occurs in a sample from the Gambatesa mine, Val Graveglia, Liguria, Italy, where it occurs as purplish black anhedral grains up to 0.1 mm in length and shows a black streak. No cleavage is observed and the Vickers hardness (VHN100) is 142 kg/mm2. Weissite is dark bluish black, weakly pleochroic, and moderately anisotropic in bluish tints. Reflectance percentages in air for Rmin and Rmax are 37.0, 38.4 (471.1 nm), 33.2, 34.2 (548.3 nm), 31.2, 32.1 (586.6 nm), and 28.6, 31.0 (652.3 nm), respectively.

Weissite is trigonal and belongs to the space group P3m1 with the following unit-cell parameters: a = 8.3124(7) Å, c = 21.546(1) Å, V = 1289.3(2) Å3, and Z = 24. Electron microprobe analyses gave the chemical formula (Cu1.62Ag0.04Au0.04Fe0.04Sb0.04)Σ=1.78(Te0.96S0.02Se0.02). The crystal structure has been solved and refined to R = 1.95%. It consists of Cu and Te polyhedra forming complex crystal-chemical environments as is typical of many intermetallic compounds. The exceedingly short bond distances observed among the metals are discussed in relation to other copper tellurides and pure metals.

Keywords

weissitevulcaniterickarditetelluridesVal GravegliaItaly
Type
Research Article
Information
Mineralogical Magazine , Volume 77 , Issue 4 , June 2013 , pp. 475 - 483
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Anthony, J.W., Bideaux, R.A., Bladh, K.W. and Nichols, M.C. (1990) Handbook of Mineralogy. Volume I: Elements, Sulfides, Sulfosalts. Mineral Data Publishing, 588 pp.Google Scholar
Baranova, R.V., Avilov, A.S. and Pinsker, Z.G. (1974) Determination of the crystal structure of the hexagonal phase bIII in the copper-tellurium system by electron diffraction. Sovie t Physics Crystallography, 18, 736–740.Google Scholar
Basso, R., Lucchetti, G. and Zefiro L. (1992) Reppiaite, Mn5(OH)4(VO4)2, a new mineral from Val Graveglia (Northern, Appenines, Italy). Zeischrift für Kristallographie, 201, 223–234.Google Scholar
Basso, R., Lucchetti, G., Zefiro, L. and Palenzona, A. (1994) Vanadomalayaite, CaVOSiO4, a new mineral vanadium analog of titanite and malayaite. Neues Jahrbuch für Mineralogie, 11, 489–498.Google Scholar
Basso, R., Lucchetti, G., Martinelli, A. and Palenzona, A. (2003) Cavoite, CaV3O7, a new mineral from the Gambatesa mine, northern Apennines, Italy. European Journal of Mineralogy, 15, 181–184.CrossRefGoogle Scholar
Basso, R., Cabella, R., Lucchetti, G., Martinelli, A. and Palenzona, A. (2005) Vanadiocarpholite, Mn2+V3+Al(Si2O6)(OH)4, a new mineral from the Molinello mine, northern Apennines, Italy. European Journal of Mineralogy, 17, 501–507.CrossRefGoogle Scholar
Basso, R., Carbone, C. and Palenzona, A. (2008) Cassagnaite, a new mineral from the Cassagna mine, northern Apennines, Italy. European Journal of Mineralogy, 20, 95–100.CrossRefGoogle Scholar
Bayliss, P. (1990) Revised unit-cell dimensions, space group, and chemical formula of some metallic minerals. The Canadian Mineralogist, 28, 751–755.Google Scholar
Bindi, L., Arakcheeva, A. and Chapuis, G. (2009) The role of silver on the stabilization of the incommensurately modulated structure in calaverite, AuTe2. American Mineralogist, 94, 728–736.CrossRefGoogle Scholar
Bindi, L., Carbone, C., Cabella, R. and Lucchetti, G. (2011) Bassoite, SrV3O7·4H2O, a new mineral from Molinello mine, Val Graveglia, eastern Liguria, Italy. Mineralogical Magazine, 75, 2677–2686.CrossRefGoogle Scholar
Blachnik, R., Lasocka, M. and Walbrecht, U. (1983) The system copper–tellurium. Journal of Solid State Chemistry, 48, 431–438.CrossRefGoogle Scholar
Brugger, J., Etschmann, B.A., Pascal, V.G., Weihua, L. Testemale, D. and Pring A. (2012) XAS evidence for the stability of polytellurides in hydrothermal fluids up to 599ºC, 800 bar. American Mineralogist, 97, 1519–1522.CrossRefGoogle Scholar
Cabella, R., Lucchetti, G. and Marescotti, P. (1998) Mnores from Eastern Ligurian ophiolitic sequences (“Diaspri di Monte Alpe” Formation, Northern Apennines, Italy). Trends in Mineralogy, 2, 1–16.Google Scholar
Carbone, C., Basso, R., Cabella, R., Martinelli, A., Grice, J.D. and Lucchetti, G. (2013) Mcalpineite from the Gambatesa mine, Italy, and redefinition of the species. American Mineralogist, submitted.CrossRefGoogle Scholar
Cherin, P. and Unger, P. (1967) Two-dimensional refinement of the crystal structure of tellurium. Acta Crystallographica, 23, 670–671.CrossRefGoogle Scholar
Crawford, WM.P. (1927) Weissite – a new mineral. American Journal of Science, 13, 345–346.CrossRefGoogle Scholar
Ibers, J.A. and Hamilton, W.C. (editors) (1974) International Tables for X-ray Crystallography, vol. IV, 366p. Kynock, Dordrecht, The Netherlands.Google Scholar
Lucchetti, G., Cabella, R. and Cortesogno, L. (1990) Pumpellyites and coexisting minerals in different low-grade metamorphic facies of Liguria, Italy. Journal of Metamorphic Geology, 8, 539–550.CrossRefGoogle Scholar
McPhail, D.C. (1995) Thermodynamic properties of aqueous tellurium species between 25 ºC and 350 ºC. Geochimica et Cosmochimica Acta, 59, 851–866.Google Scholar
Oxford Diffraction (2006) CrysAlis RED (Version 1.171.31.2) and ABSPACK in CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, UK.Google Scholar
Pals, D.W. and Spry, P.G. (2003) Telluride mineralogy of the low-sulfidation. Mineralogy and Petrology, 79, 285–307.CrossRefGoogle Scholar
Pashinkin, A.S. and Fedorov, V.A. (2003) Phase equilibria in the Cu–Te system. Inorganic Materials, 39, 539–554.CrossRefGoogle Scholar
Patzak, I. (1956) Uber die Struktur und die Lage der Phasen im System Kupfer–Tellur. Zeitschrift für Metallkunde, 47, 418–420.Google Scholar
Pertlik, F. (2001) Vulcanite, CuTe: hydrothermal synthesis and crystal structure refinement. Mineralogy and Petrology, 71, 149–154.CrossRefGoogle Scholar
Schutte, W.J. and de Boer, J.L. (1988) Valence fluctuations in the incommensurately modulated structure of calaverite AuTe2 . Act a Crystallographica, B44, 486–494.CrossRefGoogle Scholar
Schutte, W.J. and de Boer, J.L. (1993) Determination of the incommensurately modulated structure of Cu3-xTe2. Acta Crystallographica, B49, 398–403.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.CrossRefGoogle Scholar
Suh, I.-K., Ohta, H. and Waseda, Y. (1988) Hightemperature thermal expansion of six metallic elements measured by dilatation method and X-ray diffraction. Journal of Materials Science, 23, 757–760.CrossRefGoogle Scholar
Thompson, R.M. (1949) The telluride minerals and their occurrence in Canada. American Mineralogist, 34, 342–382.Google Scholar
Villars, P. and Calvert, L.D. (1985) Pearson’s Handbook of Crystallographic Data for Intermetallic Phases. American Society for Metals, 1985, vol. 2. Metals Park, Russell Township, Ohio, USA.Google Scholar
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Structure factors

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Bond distances

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