Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-24T04:05:56.971Z Has data issue: false hasContentIssue false

Silvialite, a new sulfate-dominant member of the scapolite group with an Al-Si composition near the 14/mP42/n phase transition

Published online by Cambridge University Press:  05 July 2018

D. K. Teertstra
Affiliation:
Departmenl of Geological Sciences, University of Manitoba, Winnipeg, Maniloba, Canada R3T 2N2
M. Schindler
Affiliation:
Departmenl of Geological Sciences, University of Manitoba, Winnipeg, Maniloba, Canada R3T 2N2
B. L. Sherriff
Affiliation:
Departmenl of Geological Sciences, University of Manitoba, Winnipeg, Maniloba, Canada R3T 2N2
F. C. Hawthorne
Affiliation:
Departmenl of Geological Sciences, University of Manitoba, Winnipeg, Maniloba, Canada R3T 2N2

Abstract

Silvialite, ideally Ca4Al6Si6O24SO4, is tetragonal, I4/m, Z = 2, with a = 12.160(3), c = 7.560(1) Å, V = 1117.9(8) Å3, c:a = 0.6217:1, ω = 1.583, ε = 1.558 (uniaxial negative), Dm = 2.75 g/cm3, Dcalc = 2.769 g/cm3 and H (Mohs) = 5.5. It is transparent and slightly yellow, has a good {100} cleavage, chonchoidal fracture, white streak and a vitreous lustre. It occurs in upper-mantle garnet-granulite xenoliths hosted by olivine nephelinite, from McBride Province, North Queensland, Australia. The empirical formula, derived from electron-microprobe analysis, is (Na1.06Ca2.86)(Al4.87Si7.13)O24 [(SO4)0.57(CO3)0.41]. Crystal-structure refinement shows disordered carbonate and sulfate groups along the fourfold axis. Silvialite is a primary cumulate phase precipitated from alkali basalt at 900–1000°C and 8–12 kbar under high fSO2 and fO2. The name silvialite, currently used in literature to describe the sulfate analogue of meionite, was suggested by Brauns (1914).

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aitken, B.G., Evans, H.T. Jr. and Konnert, J.A. (1984) The crystal structure of a synthetic meionite. Neues Jahrb. Mineral. Abh., 149, 309–24.Google Scholar
Baur, W.H. and Kassner, D. (1991) SADIAN90. Z. Kristallogr., Suppl. Issue 3, 15.Google Scholar
Brauns, R. (1914) Skapolithführende Auswürflinge aus dem Laacher Seegebiet. Neues Jahrb. Mineral. Geol. Paläont., 39, 79125.Google Scholar
Burns, P.C., Macdonald, D.J. and Hawthorne, F.C. (1994) The crystal chemistry of manganese-bearing elbaite. Canad. Mineral., 32, 397403.Google Scholar
Coolen, J.J.M.M.M. (1980) Chemical petrology of the Furua granulite complex, southern Tanzania. GUA (Univ. Amsterdam) Papers Geology, 1, 1258.Google Scholar
Devaraju, T.C. and Coolen, J.J.M.M.M. (1983) Mineral chemistry and P-T conditions of formation of a basic scapolite-garnet-pyroxene granulite from Doddakanya, Mysore District. J. Geol. Soc. India, 24, 404–11.Google Scholar
Edwards, A.C., Lovering, J.F. and Ferguson, J. (1979) High pressure basic inclusions from the Kayrunnera kimberlitic diatreme in New South Wales, Australia. Contrib. Mineral. Petrol., 69, 185–92.CrossRefGoogle Scholar
Goff, F., Arney, B.H. and Eddy, A.C. (1982) Scapolite phenocrysts in a latite dome, northwest Arizona U.S.A. Earth Planet. Sci. Lett., 60, 8692.CrossRefGoogle Scholar
Goldsmith, J.R. and Newton, R.C. (1977) Scapolite-plagioclase stability relations at high pressures and temperatures in the system NaAlSi3O8-CaAl2Si2O8-CaCO3-CaSO4 . Amer. Mineral., 62, 1063–81.Google Scholar
Griffin, W.L., Carswell, D.A. and Nixon, P.H. (1979) Lower-crustal granulites and eclogites from Lesotho, Southern Africa. Proc. 2nd Intl. Kimberlite Conf., 59-86.CrossRefGoogle Scholar
Hoefs, J., Coolen, J.J.M.M.M. and Touret, J. (1981) The sulfur and carbon isotope composition of scapolite-rich granulites from southern Tanzania. Contrib. Mineral. Petrol., 78, 332–6.CrossRefGoogle Scholar
Levien, L. and Papike, J.J. (1976) Scapolite crystal chemistry: Aluminium-silicon distributions, carbonate group disorder, and thermal expansion. Amer. Mineral., 61, 864–77.Google Scholar
Lin, S.-B. and Burley, B.J. (1973a) Crystal structure of a sodium and chlorine-rich scapolite. Acta Crystallogr., B29, 1272–8.CrossRefGoogle Scholar
Lin, S.-B. and Burley, B.J. (1973b) The crystal structure meionite. Acta Crystallogr., B29, 2024–6.CrossRefGoogle Scholar
Lin, S.-B. and Burley, B.J. (1975) The crystal structure of an intermediate scapolite — Wernerite. Acta Crystallogr., B31, 1806.CrossRefGoogle Scholar
Lovering, J.F. and White, A.J.R. (1964) The significance of primary scapolite in granulite inclusions from deep-seated pipes. J. Petrol., 5, 195218.CrossRefGoogle Scholar
Moecher, D.P. and Essene, E.J. (1991) Calculation of CO2 activities using scapolite equilibria: Constraints on the presence and composition of a fluid phase during high grade metamorphism. Contrib. Mineral. Petrol., 108, 219–40.CrossRefGoogle Scholar
Morimoto, N. (1988) Subcommittee on Pyroxenes, IMA: Nomenclature of pyroxenes. Mineral. Mag., 52, 535–50.CrossRefGoogle Scholar
Newton, R.C. and Goldsmith, J.R. (1976) Stability of the end-member scapolites: 3NaAlSi3O8*NaCl, 3CaAl2Si2O8*CaCO3, 3CaAl2Si2O8*CaSO4 . Z. Kristallogr., 143, 333–53.Google Scholar
Peterson, R.C., Donnay, G. and LePage, Y. (1979) Sulfate disorder in scapolite. Can. Mineral., 17, 5361.Google Scholar
Rudnick, R.L. and Taylor, S.R. (1987) The chemical composition and petrogenesis of the lower crust: A xenolith study. J. Geophys. Res., 92, 13981–4005.CrossRefGoogle Scholar
Stolz, A. (1987) Fluid activity in the lower crust and upper mantle: Mineralogical evidence bearing on the origin of amphibole and scapolite in ultramafic and mafic granulite xenoliths. Mineral. Mag., 51, 719–32.CrossRefGoogle Scholar
Sheldrick, G.M. (1990) A Crystallographic Computing Package (revision 4.1) Siemens analytical X-ray instruments. Madison, Wisconsin.Google Scholar
Teertstra, D.K. and Sherriff, B.L. (1996) Scapolite cell-parameter trends along the solid-solution series. Amer. Mineral., 81, 169–80.CrossRefGoogle Scholar
Teertstra, D.K. and Sherriff, B.L. (1997) Substitutional mechanisms, compositional trends and the end-member formulae of scapolite. Chem. Geol., 136, 233–60.CrossRefGoogle Scholar
Wolfe, S.H. and Hörz, F. (1970) Shock effects in scapolite. Amer. Mineral., 55, 1313–28.Google Scholar