Graphite vs. Diamond – Which is Harder?

If you’re wondering which is harder: diamond or graphite? Both are pure carbon, but the differences in their properties come down to their different crystal structures. They have the same basic chemistry but have distinctly different physical properties. One difference is that graphite is opaque while diamond is transparent. In fact, they are almost two different kinds of carbon. Let’s compare them to learn more about each type.

While the differences between these two materials are substantial, they’re also similar. Diamonds are used for many things, from jewelry to very sensitive thermometers. They’re also used in lasers and light-emitting diodes. Graphite is also a great lubricant, and both are extremely hard. If you’re wondering which is harder, check out these articles! You’ll be glad you did!

What’s the Difference Between Graphite and Diamond?

 These two materials are made up of carbon atoms arranged in sheets. They are held together by weak van der Waals forces, and they are both excellent conductors of electricity. Graphite is also softer than diamond, so it’s more pliable and conductive. For this reason, it’s used to make electric wires and other devices.

The Hexagonal Structure 

The hexagonal structure of graphite is the most impressive feature of this substance. Carbon atoms are bonded together in three-dimensional sheets. The arrangement of these layers is difficult to draw in 3D, but it shows the number of atoms in each layer. The layers are held together by weak intermolecular forces. These properties make graphite stronger than diamond. In addition, graphite is far less dense than a diamond, which makes it a better option for making jewelry.

Both diamond and graphite are made completely out of carbon, as is the extra currently found in buckminsterfullerene (a discrete soccer-ball-fashioned molecule containing carbon 60 atoms). The manner the carbon atoms are organized in space, however, is specific for the 3 materials, making them allotropes of carbon. The differing homes of carbon and diamond get up from their awesome crystal structures.

Carbon Atoms in Diamond 

In a diamond, the carbon atoms are organized tetrahedrally. Each carbon atom is connected to 4 different carbon atoms 1.544 x 10-10 meters away with a C-C-C bond attitude of 109. five degrees. It is a strong, inflexible 3-dimensional shape that consequences in a limitless community of atoms. This bills for diamond\’s hardness, first-rate power and sturdiness and offers diamond a better density than graphite (3.514 grams in step with cubic centimeter).

Because of its tetrahedral shape, diamond additionally indicates an exceptional resistance to compression. The hardness of a crystal is measured on a scale, devised with the aid of using Friederich Mohs, which ranks compounds in line with their capacity to scratch one another. Diamond will scratch all different substances and is the toughest fabric known (detailed as 10 on the Mohs scale).

It is the high-quality conductor of warmth that we know, engaging in as many as 5 instances of the quantity that copper does. Diamond additionally conducts sound, however now no longer electricity; it\’s far an insulator, and its electric resistance, optical transmissivity, and chemical inertness are correspondingly remarkable.

Moreover, diamonds disperse light. This means that the refractive indices for red and violet light are different (2.409 and 2.465, respectively). As a result, the gemstone acts as a prism to separate white light into rainbow colors, and its dispersion is 0.056 (the difference). The greater the dispersion, the better the spectrum of colors that is obtained. This property gives rise to the “fire” of diamonds. The “brilliance” of diamonds stems from a combination of refraction, internal reflection, and dispersion of light.

For yellow light, for example, a diamond has a high refractive index, 2.4, and a low critical angle of 24.5 degrees. This means that when yellow light passes into a diamond and hits a second face internally at an angle greater than 24.5 degrees, it cannot pass from the crystal into the outside air but instead gets reflected back to the inside of the gemstone.

Carbon Atoms in Graphite

The carbon atoms in graphite are also arranged in an infinite array, but they are layered. These atoms have two types of interactions with one another. In the first, each carbon atom is bonded to three other carbon atoms and arranged at the corners of a network of regular hexagons with a 120-degree C-C-C bond angle. These planar arrangements extend in two dimensions to form a horizontal, hexagonal “chicken-wire” array.

In addition, these planar arrays are held together by weaker forces known as stacking interactions. The distance between two layers is longer (3.347 x 10-10 meters) than the distance between carbon atoms within each layer (1.418 x 10-10 meters). This three-dimensional structure accounts for the physical properties of graphite. Unlike diamond, graphite can be used as a lubricant or in pencils because the layers cleave readily. It is soft and slippery, and its hardness is less than one on the Mohs scale.

Graphite also has a lower density (2.266 grams per cubic centimeter) than diamond. The planar structure of graphite allows electrons to move easily within the planes. This permits graphite to conduct electricity and heat as well as absorb light and, unlike diamond, appear black in color.

Graphite and diamond are the maximum thrilling minerals. They are equal chemically – each is composed of carbon (C), however physically, they may be very exclusive. Minerals that have identical chemistry however exclusive crystal systems are referred to as polymorphs.

When you have a take a observe graphite and diamond, it\’s miles difficult to assume that they may be equal chemically, for they may be so exclusive physically. Graphite is opaque and metallic- too earthy-looking, even as diamonds are obvious and brilliant.


Another crucial bodily distinction is their hardness. The hardness of minerals is in comparison to the usage of the Mohs Hardness Scale, a relative scale numbered 1 (softest) to 10 (toughest). Graphite could be very gentle and has a hardness of one to two on this scale. Diamonds are the toughest regarded herbal substance and feature a hardness of 10. No different certainly taking place substance has a hardness of 10. The crystal shape of graphite yields bodily homes that allow using graphite as a lubricant and as pencil lead. The gem and commercial homes of diamonds, bodily homes that we cherish and exploit, also are the end result of the diamond\’s crystal shape.

The motive for the variations in hardness and different bodily homes may be defined with the molecular fashions below. In graphite, the person’s carbon atoms hyperlink as much as shape sheets of carbon atoms. Each sheet of carbon atoms is translated (offset) through one-1/2 of a unit such that trade sheets are withinside the identical position. Within every sheet each carbon atom is bonded to a few adjoining carbon atoms that lie on the apices of equilateral triangles. This produces hexagonal earrings of carbon atoms. Each carbon atom has 4 valence electrons to be had to take part withinside the formation of chemical bonds. Three of those electrons are utilized in forming sturdy covalent bonds with the adjoining atoms withinside the sheet.

Covalent bonds are a form of chemical bond wherein electrons are shared among atoms. The fourth electron is unfastened to wander over the floor of the sheet making graphite an electrical conductor. The spacing among the sheets of carbon atoms is more than the diameter of the person atoms. Weak bonding forces referred to as van der Waals forces keep the sheets together. Because those forces are weak, the sheets can without difficulty slide beyond every difference. The sliding of those sheets offers graphite its softness for writing and its lubricating homes.

In diamonds, every carbon atom is strongly bonded to 4 adjoining carbon atoms placed on the apices of a tetrahedron (a three-sided pyramid). The 4 valence electrons of every carbon atom take part withinside the formation of very sturdy covalent bonds. These bonds have identical electricity in all directions. This offers diamonds their top-notch hardness. Since there aren\’t any unfastened electrons to wander via the shape, diamonds are first-rate insulators. The brilliance and “fire” of reduce diamonds is because of a totally excessive index of refraction (2.42) and the sturdy dispersion of light; homes that are associated with the shape of diamonds.

Carbon is a mineral made of various elements. The two types of carbon are known as allotropes of carbon. They differ in their chemical makeup and crystal structure. Graphite is a molecular form of carbon. While diamond is a solid, graphite is a solid that does not melt under pressure. Its properties make it suitable for jewelry-making and other applications. There are several advantages and disadvantages of graphite, which are discussed below.

More Valuable

Diamonds are more valuable than graphite. They are more difficult to cut and have higher luster, but they share many other characteristics. Diamond has more covalent bonds, which involve electron pairs between atoms. Because diamonds have more covalent bonds, they are more stable and valuable than graphite. Graphite’s bonds are weaker and are not as rigid. In comparison, diamond has fewer weaker covalent bonds.

When comparing graphite to diamond, keep in mind that both are allotropes of carbon. While they both contain carbon, their atoms are arranged differently. Diamond’s carbon atoms are bonded tightly to four other carbon atoms, while graphites are arranged in a tetrahedron shape. This tetrahedron structure creates very strong covalent bonds.

Significant Differences

Despite their similarities, graphite and diamond have some significant differences. Diamond is harder than graphite and has a much higher melting point. However, graphite is more flexible and does not conduct electricity. Diamonds are made of four different carbon atoms, and are thus incomparably harder than graphite. The difference is also apparent in their hardness, which is why they can withstand a lot of wear and tear.

Unlike diamond, graphite’s atoms are free to move in a sheet. This means that the carbons are more prone to transferring electricity when they are in contact with other materials. Because diamond is made of carbon, it has four valence electrons. While graphite has three, diamond has only three. The fourth electron can freely move through the graphite sheet. Because of this, it’s a better electrical conductor than graphite.


Because of their properties, graphite is often used in fire seals, which resists fire and smoke while keeping fumes from spreading throughout the building. Graphite also has lower specific gravity than diamond and is slightly more reactive to chemicals. When exposed to acid, graphite is oxidized to carbon dioxide. It is also used in electronic equipment and in the production of pencils. Graphite is also widely used as an electrode in many applications, including batteries.

Graphite has a similar atomic structure to diamond, but its atoms are organized differently. Diamond’s carbon atoms are arranged tetrahedrally, with strong bonds to those above them. The structure of diamond gives it its outstanding properties, including hardness. Diamond is the hardest material on the Mohs scale. You’ll find graphite in high-tech golf club shafts.