Phyllosilicates Phyllosilicates, commonly referred to as sheet silicate minerals, are a diverse and intriguing group of minerals found in the Earth's crust. These minerals are characterized by their unique crystal structure, which consists of continuous two-dimensional sheets, giving them their distinct properties and wide-ranging geological significance. One of the defining features of phyllosilicates is their atomic structure, which consists of tetrahedral and octahedral sheets. Tetrahedral sh