tetrahedrally co-ordinated level in the mica structure. The micas may be natural or synthetic. Position of the maxima of absorption is again dependent upon the dominant type of ion in the ...

Rausell-Colom, J. A., Sweatman, T. R., Wells, C. B., and Norrish, K., Experimental Pedology (edit. by Hallsworth, E. G., and Crawford, D. V.), 40 (Butterworths, 1965).