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Li-Bearing Stevensite from Moldova Nouǎ, Romania

Published online by Cambridge University Press:  02 April 2024

Virgil Ianovici ,
Gheorghe Neacşu  and
Vasilica Neacşu
Virgil Ianovici
Affiliation:
National Council for Environmental Protection, 5 Av. Ilie Pintilie, 71902 Bucharest 32, Romania
Gheorghe Neacşu*
Affiliation:
National Council for Environmental Protection, 5 Av. Ilie Pintilie, 71902 Bucharest 32, Romania
Vasilica Neacşu*
Affiliation:
National Council for Environmental Protection, 5 Av. Ilie Pintilie, 71902 Bucharest 32, Romania
*
1Geological & Geophysical Prospecting Enterprise, 1 Caransebeş Street, 78344 Bucharest 32, Romania
1Geological & Geophysical Prospecting Enterprise, 1 Caransebeş Street, 78344 Bucharest 32, Romania
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Abstract

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Li-bearing smectite minerals occurring as hydrothermal alteration products of magnesium silicate minerals in skarns associated with the Moldova Nouǎ, Romania, porphyry copper deposit were examined by X-ray powder diffraction, infrared spectroscopy, and thermal and chemical analyses. Li-bearing smectite containing 0.45–0.50 Li/unit cell is common, whereas smectite containing 0.21–0.33 Li/unit cell is less common. Both materials coexist with talc and kerolite. The Li-bearing smectite minerals (b = 9.111 Å) contains semi-ordered or ordered stacking and is highly crystalline, similar to saponite. After 3-yr storage under laboratory conditions in an air-dried state (RH = 50%) or after heating for 2 hr at 100°, 200°, 300°, or 400°C, the Li-bearing smectite minerals showed charactenstics of a regular 1:1 interstratification of anhydrous and dihydrate layers. Some segregation of the anhydrous, monohydrate, and dihydrate layers was noted.

The amount of Li-for-Mg substitution was found to be close to that in hectorite, and the number of octahedral vacancies was similar to that in stevensite. This Li-bearing smectite apparently formed directly from colloidal suspensions at atmospheric temperature and pressure.

Keywords

HectoriteHydrationInterstratificationLithiumSmectiteStevensite
Type
Research Article
Information
Clays and Clay Minerals , Volume 38 , Issue 2 , April 1990 , pp. 171 - 178
Copyright
Copyright © 1990, The Clay Minerals Society

References

Brindley, G. W., 1955 Stevensite, a montmorillonite-type mineral showing mixed-layer characteristic Amer. Mineral. 40 239 – 247.Google Scholar
Bríndley, G. W. and Brown, G., 1980 Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society.CrossRefGoogle Scholar
Deer, A. W., Howie, R. A. and Zussman, J., 1962 Rock-forming Minerals, Vol. 3, Sheet Silicates London Longmans 226 – 241.Google Scholar
Farmer, V. C., 1958 The infrared spectra of talc, saponite and hectorite Mineral. Mag. 31 829 – 845.Google Scholar
Farmer, V. C., 1974 The Infrared Spectra of Minerals London Mineralogical Society.CrossRefGoogle Scholar
Granquist, W. T., Pollack, S. S. and Swineford, A., 1960 A study of the synthesis of hectorite Clays and Clay Minerals, Proc. 8th Natl. Conf, Norman, Oklahoma, 1959 New York Pergamon Press 150 – 169.Google Scholar
Iosof, V. and Neacsu, V., 1980 Analysis of silicate rocks by atomic absorption spectrometry J. Rom. Chemistry 25 589 – 597.Google Scholar
Köster, H. M., van Olphen, H. and Veniale, F., 1982 The crystal structure of 2:1 layer silicates Proc. Int. Clay Conf, Bologna, Pavia, 1981 Amsterdam Elsevier 41 – 71.Google Scholar
Mackenzie, R. C., 1957 The Differential Thermal Investigation of Clays London Mineralogical Society 140 – 164.Google Scholar
Méring, J. and Gieseking, J., 1975 Smectites Soil Components, Vol. 2, Inorganic Components Berlin Springer-Verlag.Google Scholar
Neacşu, G., 1970 Mrazekite, a new magnesium montmo-rillonite J. Rom. Geol. 14 25 – 34.Google Scholar
Newman, A. C. D., 1968 A simple apparatus for separating fluorine from aluminosilicates by pyrohydrolysis Analyst 93 827 – 831.CrossRefGoogle Scholar
Otsu, H. and Yasuda, T., 1963 Thermal behavior of in-terlayer water in stevensite Mineral. Journal 4 91 – 114.CrossRefGoogle Scholar
Otsuka, R., Imai, M. and Sakamoto, T., 1972 Stability of stevensite under hydrothermal conditions Mem. Sci. Eng. Waseda Univ. 36 37 – 56.Google Scholar
Otsuka, R., Sakamoto, T., Suzuki, S., Shimoda, S. and Koshitu, A., 1979 Hydrothermal treatment of pectolite. Experimental studies on the genesis of stevensite and hydrated talc J. Mineral. Soc. Japan 14 170 – 186.Google Scholar
Sakamoto, T., Koshimizu, H., Shimoda, S., Otsuka, R., van Olphen, H. and Veniale, F., 1982 Hydrothermal transformation of some minerals into stevensite Proc. Int. Clay Conf. Bologna, Pavia, 1981 Amsterdam Elsevier 537 – 546.Google Scholar
Sakamoto, T., Suzuki, S., Otsuka, R. and Imai, N., 1977 Hydrothermal treatment of wollastonite and pectolite with MgCl2 solution. Experimental studies on the genesis of ste-vensite and hydrated talc J. Clay Sci. Japan 15 9 – 22.Google Scholar
Shimoda, S., 1971 Mineralogical studies of a species of stevensite from the Obori mine, Yamagata Prefecture, Japan Clay Miner. 9 185 – 192.CrossRefGoogle Scholar
Stoica, E., Bogaci, R., Vlad, L. and Constantinescu, M. (1979) Determination cation exchange properties: Technical State Standards STAS 7184, Soils. of 12 pp. (in Romanian).Google Scholar
Suzuki, S. and Otsuka, R., 1976 Hydrothermal treatment of xonolite with MgCl2 solution. Experimental studies on the genesis of stevensite and hydrated talc J. Clay Sci. Soc. Japan 16 98 – 111.Google Scholar