A process for the in-situ preparation of a composite comprising a cationic clay and binder/matrix material from sources comprising an aluminum containing source, a silicon containing source and a di-valent metal containing source comprising the steps of: a. preparing a precursor mixture by mixing the aluminum containing source, the silicon containing source and the di-valent metal containing source with seeding material, b. homogenizing the precursor mixture, and c. aging the precursor mixture to obtain the composite. One or two of the aluminum containing source, silicon containing source or di-valent metal containing source is to be in excess of the amount required for stoichiometry of the three sources with respect to the formation of the cationic clay. The excess source or sources will form the binder/matrix material of the composite. The invention also includes a body comprising a composite obtained by this process having binding/matrix material present in a discontinuous phase.