Why are clay minerals common?

Physical and Chemical Properties of Clays The characterististics common to all clay minerals derive from their chemical composition, layered structure, and size. Clay minerals all have a great affinity for water.

What are the clay minerals explain?

Definition: Clay minerals are the characteristic minerals of the earths near surface environments. They form in soils and sediments, and by diagenetic and hydrothermal alteration of rocks. Water is essential for clay mineral formation and most clay minerals are described as hydrous alumino silicates.

What is a 1 1 clay mineral?

A 1:1 clay would consist of one tetrahedral sheet and one octahedral sheet, and examples would be kaolinite and serpentinite. A 2:1 clay consists of an octahedral sheet sandwiched between two tetrahedral sheets, and examples are talc, vermiculite, and montmorillonite.

Is Mica a clay mineral?

Another common group of clay minerals, the mica group, consists of repeating T-O-T units and so is referred to as 2:1 clay minerals. The 2:1 clay minerals are some of the most common in the crust and include the highly abundant mineral smectite , vermiculite, and illite.

What are the properties of clay mineral?

The small size of the particles and their unique crystal structures give clay materials special properties. These properties include: cation exchange capabilities, plastic behaviour when wet, catalytic abilities, swelling behaviour, and low permeability.

How common is clay?

Between one-half and two-thirds of the world’s population live or work in buildings made with clay, often baked into brick, as an essential part of its load-bearing structure. Clay is a very common substance. Shale, formed largely from clay, is the most common sedimentary rock.

How many clay minerals are there?

There are three main groups of clay minerals: Kaolinite – also includes dickite and nacrite; formed by the decomposition of orthoclase feldspar (e.g. in granite); kaolin is the principal constituent in china clay.

What are basic units of clay minerals?

Actually there are two units in the fundamental structure of clays: tetrahedron and octahedron. In each tetrahedron, Si4+ in the center is surrounded by four O2− at the corners. Then they share oxygen with each other to form a tetrahedral sheet. Similarly, a metal cation is at the center and six O2− are in the corners.