Abstract: | By treatment of muscovite with molten lithium nitrate at 300 degrees 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 2M(1) muscovite) decreases from 9.024 to 8.988 A 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 d(001) upon re-saturation with potassium. |