Abstract
The western region of the Deccan Volcanic Province (DVP) is constituted of tholeiitic lava flows. They host numerous cavities, varying in size and shape, largely occupied by zeolites and a variety of secondary minerals, amongst which the fibrous zeolites (natrolite group), are particularly gorgeous and attractive. Scolecite and mesolite are the only two members commonly occurring in this region. Our data on their thermal behaviour significantly differs from that reported in previous literature. Scolecite, Ca8(Al16Si24O80)·24H2O shows three distinct steps instead of two and water loss is observed even beyond 550°C. It is held that the first step corresponds to the expulsion of water from the site farthest away from Ca and the next two steps in succession correspond to the two sites nearer to Ca. Mesolite, Na16Ca16(Al48Si72O240)· 64H2O has much more complex behaviour with four or five steps of water expulsion and a major loss around 248–270°C in a double reaction attributed here to the expulsion of water from scolecite type channels. It is further held that the natrolite type channels are emptied in further steps. Loss of water in steps even beyond 400°C is particularly noted and such reactions are well reflected in the TG and the DTG. Peak temperature dependence on sample amounts is also evident. Successive phase transformations above 700°C, up to 1000°C are reflected in the DTA curves.
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References
R. N. Sukheswala, R. K. Avasia and M. Gangopadhyay, Min. Mag., 39 (1974) 658.
A. Alberti, D. Pongiluppi and G. Vezzalini, Neues Jahrb. Miner. Abhandlungen, 143 (1982) 231.
M. Koizumi, Miner. J., 1 (1953) 36.
E. Pecsi-Donath, Acta Geol. VI Fasc., 3–4 (1962) 429.
L. P. Van Reeuwijk, Am. Mineral., 57 (1972) 499.
G. Gottardi and E. Galli, Natural Zeolites, Springer Verlag, (1985) 409.
L. Pauling, Proc. Nat. Acad. Sci. USA, 16 (1930) 453.
W. H. Taylor, C. A. Meek and W. W. Jackson, Z. Kristallogr., 84 (1933) 373.
G. Adiwidjaja, Diss. Univ. Hamburg, 1972. (In: G. Gottardi and E. Galli) Natural Zeolites, Springer-Verlag, 1985.
V. N. Sveshnikov and V. G. Kusnetzov, Izvest. Akad. Nauk, USSR. Otdel. Khim. Nauk., (1946) 25.
C. Y. Peng, Am. Mineral., 40 (1955) 834.
E. Pecsi-Donath, Acta Geol. IX (1965) 235.
E. Pecsi-Donath, Acta Miner. Petr. XVII Fasc., 2 (1966) 143.
E. Pecsi-Donath, Acta Miner. Petr. XVIII Fasc., 2 (1968) 127.
L. P. Van Reeuwijk, Meded. Landbouwhoogesch. Wageningen., 74 (1974) 1–88.
S. Varadarajan and Desh Mittra, Ind. Mineralogist, 24 (1984) 244.
D. R. Peacor, Am. Mineral., 58 (1973) 676.
A. Alberti and G. Vezzalini (in: G. Gottardi and E. Galli, 1985), Natural Zeolites, Springer Verlag, 1983, p. 409.
M. H. Hey, Min. Mag., 23 (1932) 243.
M. D. Foster, US Geol. Surv. Prof. Pap. 504-D (1965) E:D1-E10.
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The authors gratefully record their sincere thanks to Shri. K. L. Gadre, of Pune for a handsome donation to support the work on zeolites. Dr. A. Y. Bhale, and Shri. M. B. Makki, of Pune have very generously provided help in sample collection. The authors are thankful to the Head, Geology Department, University of Pune, for providing facilities for this work. We are highly indebted to Janos Kalmár of Hungarian Geological Survey, and Dr. Vivek S. Kale and Dr. Himanshu Kulkarni for their valuable help in preparing illustrations and critically reading the manuscript. The first author (AA) acknowledges with thanks the grants provided by the CSIR, New Delhi, through Research Fellowship (SRF), and partial Travel Grant for attending the IMA'94 at Pisa, Italy.
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Apte, A., Phadke, A.V. Thermal behaviour of fibrous zeolites of the natrolite group. Journal of Thermal Analysis 50, 473–486 (1997). https://doi.org/10.1007/BF01980507
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DOI: https://doi.org/10.1007/BF01980507