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Chemical changes during the alteration of micas

Published online by Cambridge University Press:  09 July 2018

A. C. D. Newman  and
G. Brown
A. C. D. Newman
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts
G. Brown
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts
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Abstract

Di- and trioctahedral micas were altered to vermiculite-like minerals by extracting the K with sodium tetraphenylboron. Chemical analysis of original and altered micas shows that loss of K is accompanied by an increased loss on ignition, oxidation of some Fe2+ to Fe3+, loss of divalent octahedral cations, mainly Mg2+, loss of OH− (or sorption of H+) and decrease in net negative charge.

The following reactions are suggested to explain these changes: (1) replacement of K by Na at interlayer sites; (2) release of structural OH− ions exposed by replacement of K, which decreases the negative charge and allows the structure to expand and more K to be replaced; (3) oxidation of Fe2+ ions by the reaction

4Fe2+ + 4 structural (OH−) + O2 → 4Fe3+ + 4 structural (O2−) + 2H2O;

and (4) release of divalent octahedral ions, possibly through some of the holes left when structural OH− is lost.

The wide implications of these proposals are discussed.

Type
Research Article
Information
Clay Minerals , Volume 6 , Issue 4 , December 1966 , pp. 297 - 310
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1966

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References

Addison, C.C., Addison, W.E.. Neal, G.H. & Sharp, J.H. (1962) J. chem. Soc. 1468.Google Scholar
Addison, W.E. & Sharp, J.H. (1962) Clay Miner. Bull. 5, 73.Google Scholar
Addison, W.E. & Sharp, J.H. (1963) Clays Clay Miner. 11. 95.CrossRefGoogle Scholar
Bassett, W.A. (1960) Bull. geol. Soc. Am. 71. 449.CrossRefGoogle Scholar
Bradley, W.F. & Serratosa, J.M. (1960)'Clays Clay Miner. 7, 260.Google Scholar
Brindley, G.W. & Youell, R.F. (1953) Mineralog. Mag. 30. 57.Google Scholar
Denison, I.A., Fry, W.H. & Gile, P.L. (1929) Tech. Bull. U.S. Dept. Agric. No. 128.Google Scholar
Foster, M.D. (1963) Clays Clay Miner. 10, 70.Google Scholar
Gastuche, M.C. (1963) 1st Int. Clay Conf., Proc. (Rosenqvist, I. Th. and Graff-Petersen., P. editors), Vol. I, p. 67. Pergamon Press, Oxford.Google Scholar
Gruner, J.W. (1934) Am. Miner. 19. 557.Google Scholar
Hanway, J.J. (1956) Iowa State Coll. J. Sci. 30, 374.Google Scholar
Hodgson, A.A., Freeman, A.G. & Taylor, H.F.W. (1965a) Mineralog. Mag. 35, 5.Google Scholar
Hodgson, A.A., Freeman, A.G. & Taylor, H.F.W. (1965b) Mineralog. Mag. 35. 455.Google Scholar
Marshall, CE. & Mcdowell, L.L. (1965) Soil Sci. 99. 115.Google Scholar
Mortland, M.M. (1958) Proc. Soil Sci. Soc. Am. 22, 503.Google Scholar
Mortland, M.M. & Lawton, K. (1961) Proc. Soil Sci. Soc. Am. 25, 473.Google Scholar
Rausell-Colom, J.. Sweatman, T.R.. Wells, C.B. & Norrish, K. (1965) Experimental Pedology. Proc. 11th School Agric Sci. Nottingha. (Hallsworth, E. G. and Crawford, D. V., editors), p. 40. Butterworths. London.Google Scholar
Rich, C.I. & Black, W.R. (1964) Soil Sci. 97, 384.Google Scholar
Scott, A.D. & Reed, M.G. (1962) Proc. Soil Sci. Soc. Am. 26, 41.Google Scholar
Shapiro, L. & Brannock, W. (1956) Bull. U.S. geol. Surv. No. 1036-C.Google Scholar
Smith Aitken, W.W. (1965) Mineralog. Mag. 35. 151.Google Scholar
Tucker, B.M. (1964) Austr. J. Soil Res. 2, 56.Google Scholar
Walker, G.F. (1949) Mineralog. Mag. 28, 693.Google Scholar
Walker, G.F. (1957) Clay Miner. Bull. 3, 154.Google Scholar
Walker, G.F. (1958) Clay Miner. Bull. 3, 302.Google Scholar
White, J.L. (1950) Proc Soil Sci. Soc Am. 15. 129.Google Scholar
Zen-e-an, & Albee, A.L. (1964) Am. Miner. 49, 904.Google Scholar