The phyllosilicates are characterized by sheets of linked silicate tetrahedra.
The term “phyllon” comes from the Greek word meaning “leaf.” This is because all of the members of this class of silicates have platy or flaky habit and one prominent cleavage. The minerals are generally soft, of relative low specific gravity and may even have a greasy feel. Cleaved samples can show flexibility or even elasticity, if the sheets are thin enough.