Removal of Potassium Alters b-Dimension of Muscovite

See allHide authors and affiliations

Science  04 Jan 1963:
Vol. 139, Issue 3549, pp. 39-40
DOI: 10.1126/science.139.3549.39


By treatment of muscovite with molten lithium nitrate at 300°C we have been able to remove a large portion of the interlayer potassium and observe a decrease in the apparent b-axis length as a function of potassium content over the range of 8.8 to 0.7 percent potassium. The b-axis length of Silversheen mica (a 2M1 muscovite) decreases from 9.024 to 8.988 Å as the potassium content decreases from 8.79 to 3.31 percent. The contraction of the b-dimension results in an effective decrease in the size of the ditrigonal opening in the planar surfaces with a consequent increase in the d001 upon re-saturation with potassium.