Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-13T13:48:39.375Z Has data issue: false hasContentIssue false

Sugilite in manganese silicate rocks from the Hoskins mine and Woods mine, New South Wales, Australia

Published online by Cambridge University Press:  05 July 2018

Y. Kawachi
Affiliation:
Geology Department, University of Otago, P.O.Box 56, Dunedin, New Zealand
P. M. Ashley
Affiliation:
Department of Geology and Geophysics, University of New England, Armidale, NSW 2351, Australia
D. Vince
Affiliation:
1A Ramsay Street, Essendon, Victoria 3040, Australia
M. Goodwin
Affiliation:
P.O.Box 314, Lightning Ridge, NSW 2834, Australia

Abstract

Sugilite relatively rich in manganese has been found at two new localities, the Hoskins and Woods mines in New South Wales, Australia. The occurrences are in manganese-rich silicate rocks of middle to upper greenschist facies (Hoskins mine) and hornblende hornfels facies (Woods mine). Coexisting minerals are members of the namansilite-aegirine and pectolite-serandite series, Mn-rich alkali amphiboles, alkali feldspar, braunite, rhodonite, tephroite, albite, microcline, norrishite, witherite, manganoan calcite, quartz, and several unidentified minerals. Woods mine sugilite is colour-zoned with pale mauve cores and colourless rims, whereas Hoskins mine sugilite is only weakly colour-zoned and pink to mauve. Within single samples, the chemical compositions of sugilite from both localities show wide ranges in Al contents and less variable ranges of Fe and Mn, similar to trends in sugilite from other localities. The refractive indices and cell dimensions tend to show systematic increases progressing from Al-rich to Fe-Mn-rich. The formation of the sugilite is controlled by the high alkali (especially Li) and manganese contents of the country rock, reflected in the occurrences of coexisting high alkali- and manganese-bearing minerals, and by high fo2 conditions.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

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

Armbnxster, T. and Oberhansli, R. (1988) Crystal chemistry of double-ring silicates: Structure of sugilite and brannockite. Amer. Mineral., 73, 595–600.Google Scholar
Armbruster, T., Oberhansli, R. and Kunz, M. (1993) Taikanite, BaS^Mn^C^Si^tO^], from the Wes-sels mine, South Africa: A chain silicate related to synthetic Ca3Mnl+O2[Si4Oi2]. Amer. Mineral., 78, 1088–95.Google Scholar
Ashley, P. M. (1986) An unusual manganese silicate occurrence at the Hoskins mine, Grenfell district, New South Wales. Austr. J. Earth Sci., 33, 443–56.CrossRefGoogle Scholar
Ashley, P. M. (1989) Geochemistry and mineralogy of tephroite-bearing rocks from the Hoskins manganese mine, New South Wales, Australia. Neues Jahrb. Mineral. Abh. 161, 85–111.Google Scholar
Brown, R. E., Brownlow, J. W. and Krynen, J. P. (1992) Manilla-Narrabri 1:250000 Metallogenic Map SH/56-9, SH/55-12: Metallogenic Study and Mineral Deposit Data Sheets. Geological Survey of New South Wales, Sydney. 319 pp.Google Scholar
Cabella, R., Lucchetti, G. and Palenzona, A. (1990) Al-rich, Fe-poor manganoan sugilite in a pecto-lite-bearing assemblage from Cerchiara Mine (Northern Apennines, Italy). Neues Jahrb. Mineral. Mh., 10, 443–8.Google Scholar
Cerny, P., Hawthorne, F. C. and Jarosewich, E. (1980) Crystal chemistry of milarite. Can. Mineral, 18, 41–57.Google Scholar
Clark, A. M., Bearne, G. S., Fejer, E. E., Din, V. K. and Couper, A. G. (1980) Additional data on sugilite. Mineral. Mag., 43, 947–9.CrossRefGoogle Scholar
Dixon, R. D. (1985) Sugilite and associated minerals from Wessels mine, Kalahari manganese field. Trans. Geol. Soc. S. Africa, 88, 11–17.Google Scholar
Dixon, R. D. (1989) Sugilite and associated meta-morphic silicate minerals from Wessels mine, Kalahari manganese field. Bull. Geol. Surv. S. Africa, 93, 1–47.Google Scholar
Droop, G. T. R. (1987) A general equation for estimating Fe3 + concentrations in ferromagnesian silicates and oxides from microprobe analyses, using stoichiometric criteria. Mineral. Mag., 51, 431–5.CrossRefGoogle Scholar
Dunn, P. J., Brummer, J. J. and Belsky, H. (1980) Sugilite, a second occurrence: Wessels mine, Kalahari manganese field, Republic of South Africa. Can. Mineral., 18, 37–9.Google Scholar
Eggleton, R. A. and Ashley, P. M. (1989) Norrishite, a new manganese mica, K(Mn2ti)Si4O12, from the Hoskins mine, New South Wales, Australia. Amer. Mineral., 74, 1360–7.Google Scholar
Eggleton, R. A. and Ashley, P.M. (1994) Namansi-lite, NaMn3 + Si2O6 pyroxene, from the Hoskins mine, New South Wales, Australia. Neues Jahrb. Mineral, (in press).Google Scholar
Hawthorne, F. C, Kimata, M., Cerny, P., Ball, N., Rossman, G. R. and Grice, J. D. (1991) The crystal chemistry of the milarite-group minerals. Amer. Mineral., 76, 1836–56.Google Scholar
Hirowatari, F. and Fukuoka, M. (1988) Some problems of the studies on the manganese minerals in Japan, (in Japanese) J. Mineral. Soc. Japan, 18, 347–65.Google Scholar
Jaffe, H. W. (1988) Crystal Chemistry and Refractivity. Cambridge University Press, Cambridge. 335 pp.Google Scholar
Kato, T., Miura, T. and Murakami, N. (1976) Crystal structure of sugilite. Mineral. J., 8, 184–92.CrossRefGoogle Scholar
Kawachi, Y. (1987) Rhodonite and serandite in the manganese deposits in Tamworth-Manilla region, New South Wales, Australia. In Preliminary Report on the Geology of the New England Fold Belt, Australia. No.l. (Iwasaki, M., project leader), Cooperative Research Group of Japan and Australia, 159-77.Google Scholar
Kawachi, Y. (1991) ‘Rhodonite'-bearing manganese deposits in the New England fold belt of eastern Australia, with special reference to the deposit of Woods mine. In Bending of the Great Serpentine Belt and Tectonic History of the Arc-type Crust around the Belt, Eastern Australia. Preliminary Report on the Geology of the New England Fold Belt, Australia. No.2. (Honma, H., project leader), Cooperative Research Group of Japan and Australia, 55—61.Google Scholar
Kawachi, Y. and Coombs, D. S. (1993) Namansilite, NaMn3 + Si206: a widespread clinopyroxene? Mineral. Mag., 57, 533–8.CrossRefGoogle Scholar
Murakami, N., Kato, T., Miura, Y. and Hirowatari, F. (1976) Sugilite, a new silicate mineral from Iwagi Islet, southwest Japan. Mineral. J., 8, 110–21.CrossRefGoogle Scholar
Sakae, T. (1986) A least squares program for calculation of unit-cell dimensions, (in Japanese) Earth Sci., 40, 207–20.Google Scholar