Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-10T10:26:19.985Z Has data issue: false hasContentIssue false

Hydrous gem magnesian cordierite with inclusions of hydroxyapatite, dolomite, and rutile

Published online by Cambridge University Press:  05 July 2018

Giorgio Graziani
Affiliation:
Istituto di Mineralogia e Petrografia, Università degli Studi, 00100 Roma, Italy
Gioli Guidi
Affiliation:
Istituto di Mineralogia e Petrografia, Università degli Studi, 00100 Roma, Italy

Summary

An uncommon sample of a pale-blue Madagascar cordierite and its mineral inclusions of different kinds have been studied. The physical properties of the embedding cordierite are: α = 1·528, β = 1·522, γ = 1·537, δ = 0·009, 2Vα = 96°, density = 2·534 g/cm3, a = 17·082 Å, b = 9·728, c = 9·352, Δ = 0·26. The electron probe analysis gave SiO2=48·64%, Al2O3 = 35·08, FeO = 0·70, MgO = 12·35, H2O+ = 2·50. This is therefore a hydrous magnesian cordierite. Its structural state is related to the shift in α, β, γ, 2Vα, and Δ with heating. Probe analyses were performed on the inclusions: hydro-xyapatite, dolomite, and rutile. The occurrence of dolomite suggests the conditions of formation of the host mineral.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1978

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

Ashworth, (J. R.) and Chinner, (G. A.), 1978. Contrib. Mineral. Petrol. 65, 379-94.CrossRefGoogle Scholar
Byström, (A.) 1942. Arkiv Mineral. Geol. 15B, 17, 12.Google Scholar
Gibbs, (G. V.), 2966. Am. Mineral. 51, 1068-87.Google Scholar
Hensen, (B. J.), 1977. Tectonophysics, 43, 7388.CrossRefGoogle Scholar
Hensen, (B. J.) and Green, (D. H.), 1972. Contrib. Mineral. Petrol. 35, 331-54.CrossRefGoogle Scholar
Hensen, (B. J.) and Green, (D. H.), 1973. Ibid. 38, 151-66.Google Scholar
Holdaway, (M. J.) and Lee, (S. M.), 1977. Contrib. Mineral. Petrol. 63, 175-98.CrossRefGoogle Scholar
liyama, (T.), 1956. Mineral. J. Japan, 1, 6, 372-94.Google Scholar
liyama, (T.), 1958. Compt. Rend. Acad. Sci. Paris. 246, 795-8.Google Scholar
Langer, (K.) and Schreyer, (W.), 1969. Am. Mineral. 54, 1442-59.Google Scholar
Miyashiro, (A.), 1957. Am. J. Sci. 255, 4362.CrossRefGoogle Scholar
Miyashiro, (A.), Iiyama, (T.), Yamasaki, (M.) and Miyashiro, (T.), 1955. Am. J. Sci. 253, 185208.CrossRefGoogle Scholar
Newton, (R. C.), 1972. J. Geol. 80, 398420.CrossRefGoogle Scholar
Puhan, (D.), 1978. Neues Jahrb. Mineral. Mh. 110–27.Google Scholar
Schreyer, (W.), 1976. Tectonophysics, 43, 127-44.CrossRefGoogle Scholar
Schreyer, (W.) and Schairer, (J. F.), 1961. J. Petrol. 2, 324406.CrossRefGoogle Scholar
Schreyer, (W.) and Yoder, (H. S., Jr.), 1964. Neues Jahrb. Mineral. Abh. 101, 271342.Google Scholar
Thompson, (A. B.), 1976. Am. J. Sci. 276, 425-54.CrossRefGoogle Scholar
Winkler, (H. G. F.), 1976. Petrogenesis of Metamorphic Rocks. 4th edn., New York, Heidelberg, Berlin (Springer-Verlag Inc.).CrossRefGoogle Scholar