Figure 1

Model of the crystal structure of muscovite mica. The elements are colour coded Red = Oxygen, Grey = Aluminium, Pink = Potassium and Yellow = Silicon. Each mica sheet consists of an aluminium octahedron layer (aluminium, oxygen, hydrogen) sandwiched between two tetrahedron layers (silicon, aluminium, oxygen). Three sheets of mica are shown and potassium ions intercalate in-between these sheets. The mica cleaves readily between the potassium ion planes yielding a step height on exfoliation of 1.0 nm. The model is generated based on the reported literature²⁴.