Diamond and Graphite

JEE Crash Course 2022

Introduction to Diamond and Graphite

Diamond and Graphite are called the allotropes of carbon. Chemically, these minerals consist of carbon atoms with different physical properties. In general, these minerals are known referred to be as polymorphs, with the same type of chemistry, but of the different crystalline structures.

In these carbon allotropes, the atoms consisting of carbon atoms in Diamond and Graphite, are bound together by strong covalent bonds of different arrangements.

Precious stone and Graphite both have shift structures, and both are pure carbon, which represents their diverse properties. However, the particles of Graphite join the three atoms of carbon and get associated with the plates, parallel to each other. The Diamond particles enter the four atoms of carbon in a gem frame.

[Image to be added Soon]

Let us understand the structure and the uses of Diamond and Graphite in detail.

Structure of Diamond and Uses

Structure of Diamond

All carbon atoms of the Diamond are said to possess strong chemical bonds of the four other carbon atoms, thereby making a perfect tetrahedron structure and on completely the crystal. Here, the carbon atoms are of sp3 hybridized, and the bond lengths of the carbon-carbon atom are equal. Therefore, the Diamond forms a three-dimensional network with strong covalent bonds.

Diamond has a melting point of about 3843 K, which is very high, and a high density of about 3.51 g/cm3. Since its valence electrons involved in the C-C sigma covalent bonds, it is known to be a poor conductor of electricity, and thus they are localized and are not free to conduct the electricity.

Mechanical Properties of Diamond

  • Hardness

Diamond is the hardest and naturally known material on both the Vickers and Mohs scale. The great hardness of Diamond relative to other materials has been known since antiquity and is the source of its name.

  • Toughness

Another mechanical property somewhat related to hardness is the toughness. It is the ability of the material to resist breakage from forceful impact. The toughness of a natural diamond has been found, when measured as, 7.5–10 MPa · m1/2.

Uses and Applications of Diamond

Some uses and applications of Diamond are listed below.

  • Diamond is a well-known material to be the hardest substance on Earth. It is used in the making tools which are utilized for cutting, grinding, drilling, and more.

  • Diamond is used to manufacturing filaments that are made of tungstens, used in light bulbs

  • Diamond is used in the jewelry making

  • They are used by most of the surgeons in the process of cataract removal from the eyes as a high precision instrument

  • The Diamond's hardness makes it very useful for purposes where extremely tough material is needed

  • The cutting edges of discs are used to cut the bricks and concrete are tipped with diamonds

Let us understand the structure of Diamond and Graphite.

Structure of Graphite and Uses

Structure of Graphite

All the carbon atoms present in the Graphite are said to have the stable chemical bonds compared to that of the other three carbon atoms, thus making the sheets that look like a chicken wire; the weak form of the forces that hold the sheet quickly. When we are composing with a pencil on a paper, it is these sheets that separately slide to desert the graphite pieces as a blemish on the Paper.

The carbon atoms present in the Graphite structure or graphite molecular structure are of sp2 hybridized, and they are directed in the same plane, thus forming the hexagonal rings. The rings have several layers of particles. Graphite is said to exhibit a low electrical conductivity of a low density of about 2.26 g/cm3.

Types and Varieties of Graphite

The principal types of a natural Graphite, each occurring in various types of ore deposits, are given below.

  • Flake graphite or small crystalline flakes of Graphite occurs as flat, isolated, plate-like particles with hexagonal edges if unbroken. Edges can be irregular or angular when broken

  • Amorphous Graphite, very fine flake graphite, sometimes called an amorphous

  • Lump or vein graphite forms in fractures or fissure veins and tends to be large platy intergrowths of acicular or fibrous crystalline aggregates, and is possibly hydrothermal in nature

  • Highly ordered pyrolytic Graphite called Graphite with an angular spread between the graphite sheets of below 1°

  • Sometimes, the name "graphite fiber" is used to refer to carbon-fiber-reinforced polymer or carbon fibers

Uses and Applications of Graphite

  • The weak intermolecular forces of Graphite make it a useful material

  • Graphite powder can be utilized as a lubricant in the form of powder or dispersion material

  • It is widely used as a lead in pencils, mixed with clay

  • Graphite is used in the electrode manufacturing of carbon, employed in the electrolytic cells because it is an excellent conductor of electricity

  • Damond can also utilize in the making of graphite crucibles because it possesses high melting points

  • It is widely used in moderators and nuclear reactors

  • Also, Graphite is used to make the non-reactive electrodes for electrolysis since it can conduct electricity without participating in the process chemically

FAQs (Frequently Asked Questions)

1. Explain the Occurrence of Graphite?

Graphite happens in metamorphic rocks as a result of the sedimentary reduction of carbon compounds during metamorphism. Graphite also occurs in meteorites and igneous rocks. Minerals that are associated with Graphite include calcite, quartz, tourmaline, and micas. The principal export sources of the mined Graphite are in tonnage order: China, Canada, Mexico, Madagascar, and Brazil.

Graphite occurs in meteorites with silicate and troilite minerals. Small graphitic crystals in meteoritic iron are known as Cliftonite. Some microscopic grains have distinctive isotopic compositions, to indicate that they were formed before the Solar system. They are one of about 12 well-known types of minerals which predate the Solar System and also have been detected in the molecular clouds. These minerals were also formed in the ejecta when the supernovae exploded or low- to intermediate-sized stars expelled their outer envelopes late in their lives. Maybe, Graphite is the second or third oldest mineral in the Universe.

2. Explain the Material Properties of Diamond?

The Diamond is a solid form of pure carbon where the atoms are arranged in a crystal. Solid carbon is available in various forms called allotropes based on the chemical bond type. Diamond is one of the most common allotropes of pure carbon. In Diamond, the bonds are sp3 orbital hybrids, and the atoms form tetrahedra with each bound to four nearest neighbors. 

Tetrahedra are rigid, and the bonds are strong, and with all known substances, per unit volume, Diamond has the greatest number of atoms, which is why it is both the least and the hardest compressible. It also has a greater density, ranging from 3520 kg/m3 in pure Diamond, and 3150 to 3530 kilograms per cubic metre (which is about three times the water density) in natural diamonds.