The material is a three-dimensionally microporous layered silicate, and is obtained in a highly crystalline form, which remains crystalline up to 723 K with little lattice contraction. There are channels in the silicate layers, including pores perpendicular to the layers, the layers being bonded by cations. The structure may be altered by substituting alternative ions. Layers may be delaminated to produce single porous silicate layers. In another aspect, the material can include a polymer to produce a composite material.