Classification of clay minerals
What are the main types of clay minerals?
These minerals can be classified on the basis of variations of chemical composition and atomic structure into nine groups: (1) kaolin-serpentine (kaolinite, halloysite, lizardite, chrysotile), (2) pyrophyllite-talc, (3) mica (illite, glauconite, celadonite), (4) vermiculite, (5) smectite (montmorillonite, nontronite, …
What is the three main groups of clay minerals?
Structure of the three major clay mineral groups: (a) kaolin, (b) smectite, and (c) mica. Figures show the stacking of Si tetrahedra and Al octahedra and characteristic basic spacing.
What are the characteristics of clay minerals?
Clay minerals all have a great affinity for water. Some swell easily and may double in thickness when wet. Most have the ability to soak up ions (electrically charged atoms and molecules) from a solution and release the ions later when conditions change. Water molecules are strongly attracted to clay mineral surfaces.
Is clay minerals a primary mineral?
Clay minerals ultimately form from the alteration of primary silicate minerals. These primary phases form from the crystallization of magma at high temperature and a range of pressures in the Earth’s crust.
How many types of 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 the 4 main properties of clay?
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.
What are the 3 types of silicate clays?
On the basis of number and arrangement of tetrahedral and octahedral sheets, silicate clays are classified into 3-different groups: 1. 1:1 Type Clay Minerals 2. 2:1 Type Minerals 3. 2: 1:1 Type Minerals.
What is the Group of clay mineral which is known as a 3 layered silicate clay or a 2 1 Non expanding type of clay?
2:1:1 Type Minerals: This silicate group is represented by chlorites. Chlorites are basically iron magnesium silicates with some aluminum present. In a typical chlorite clay crystal, 2:1 layers, such as in vermiculites, alternate with a magnesium dominated tri-octahedral sheet, giving a 2:1:1 ratio.
What mineral is the origin of most clay minerals?
Clay minerals are layer silicates that are formed usually as products of chemical weathering of other silicate minerals at the earth’s surface. They are found most often in shales, the most common type of sedimentary rock.
What is the structure of clay minerals?
The atomic structure of the clay minerals consists of two basic units, an octahedral sheet and a tetrahedral sheet. The octahedral sheet is comprised of closely packed oxygens and hydroxyls in which aluminum, iron, and magnesium atoms are arranged in octahedral coordination (Fig. 1).
What is a 2 1 clay mineral?
A 2:1 clay consists of an octahedral sheet sandwiched between two tetrahedral sheets, and examples are talc, vermiculite, and montmorillonite.
What are types of silicate clay minerals?
Different combinations of these two general structural units (tetrahedral and octahedral sheets) form the structures of the various layer silicates like mica, vermiculite, montmorillonite, chlorite, kaolinite and other interstratified and intergradient layer silicates.
What are the two general types of clays?
There are two types of clay deposits: primary and secondary. Primary clays form as residual deposits in soil and remain at the site of formation. Secondary clays are clays that have been transported from their original location by water erosion and deposited in a new sedimentary deposit.
What is meant by clay mineral?
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 are 5 uses of clay?
Bricks, cooking pots, art objects, dishware and even musical instruments such as the ocarina are all made with clay. Clay is also used in many industrial processes, such as paper making, cement production, pottery, and chemical filtering.
What is the difference between clay and clay mineral?
Clay is natural, fine-grained (<2 or <4 μm), mainly constituted of phyllosilicates, plastic (except flint clays ), and hardens on drying or firing. On the other hand, clay mineral is natural or synthetic, without size criterion, might include nonphyllosilicates, plastic, and hardens on drying or firing.
What kind of material is clay?
Clay is a soft, loose, earthy material containing particles with a grain size of less than 4 micrometres (μm). It forms as a result of the weathering and erosion of rocks containing the mineral group feldspar (known as the ‘mother of clay’) over vast spans of time.
Is clay a secondary mineral?
When rock minerals undergo a transformation process due to the change of temperature and pressure (such as metamorphism and weathering), the newly created stable minerals are known as the secondary minerals. For example, clay minerals are secondary minerals produced during the process of weathering.
What type of rock is clay?
sedimentary rock
Clay is a sedimentary rock made of tiny particles which come from the weathering of other rocks and minerals. The particles can be transported by rivers or ice and then deposited.
What are the 5 types of clay?
Ceramic clays are classified into five classes; earthenware clays, stoneware clays, ball clays, fire clays and porcelain clays.
What is clay and types of clay?
Kinds of Clay
The three most common types of clay are earthenware, stoneware, and kaolin. Earthenware, or common clay, contains many minerals, such as iron oxide (rust), and in its raw state may contain some sand or small bits of rock.