Exchange Properties of the Aluminosilicates

The ideal constitution of the kaolin layer represents an electrically neutral unit, with rarely any isomorphous substitution of cations of different charges within the lattice. Consequently, kaolinite and related minerals would not be expected to show a large cation exchange capacity, and indeed this is usually the case. That a small but varying exchange capacity does occur may be attributed to two principal causes. 

O Oxygen Hydroxyl O Aluminium, iron,mognesium o and Silicon, occasionally aluminium 

The hydrogen of exposed hydroxyls. A further contribution to the exchange capacity of clay minerals is made by the hydrogens of 

Some of these minerals possess high cation exchange capacities greatly in excess of that attributable to surface area, crystal fracture and edge effects. The reason for this difference in behaviour arises out of a third and major cause of exchange capacity, namely isomorphous 

1 Demonstration of the Nature of Inter-lamellar Bonding within Double Layer Aluminosilicates 

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