Described is a process for the preparation of a crystallised lamellar
solid formed by magadiite consisting of implementing in a step (i) mixing
of at least one silica source, at least one salt of
N,N,N',N'-tetramethyl-N,N'-dibenzyloctanediammonium, at least one alkali
and/or alkaline earth metal M and water and then implementing in a step
(ii) hydrothermal treatment of said mixture until said crystallised
lamellar solid constituted by magadiite is formed.