Clay minerals are a diverse group of minerals that are fine grained and crystalline and ultimately form from the aqueous alteration of primary igneous minerals at or near the surface of the Earth. They have a layered structure, commonly consisting of repeating sheets of Si tetrahedra and Al octahedra. The wide diversity of clay minerals stems from the way that these sheets stack together and the identity of ions that commonly substitute into the clay mineral structure. Due to their unique layered structure and their effectiveness as ion exchangers, the formation of clay minerals can have a significant impact over the chemical and isotopic compositions of solid and fluid phases during weathering.
Clay minerals are a highly diverse and abundant group of minerals that derive from the interaction of water with rock in the Earth’s crust. Because clay minerals are often found in the clay-size fraction of sediments and soils (i.e., below 2 μm), the terms “clay” and.
