Difference Between Diamond Graphite and Fullerene

The key difference between diamond graphite and fullerene is that diamond has a diamond cubic crystal structure and graphite has a hexagonal crystal structure, while fullerene occurs as a large spheroidal molecule.

Diamond, graphite and fullerene are different allotropes of the chemical element carbon. All these compounds have only carbon atoms in the composition, but the arrangement of the carbon atoms differ from each other.

CONTENTS

1. Overview and Key Difference
2. What is Diamond  
3. What is Graphite
4. What is Fullerene
5. Side by Side Comparison – Diamond vs Graphite vs Fullerene in Tabular Form
6. Summary

What is Diamond?

Diamond is an allotrope of carbon, which has the diamond cubic crystal structure. It is in the solid-state at standard temperature and pressure. Furthermore, it has the highest hardness among all materials and highest thermal conductivity as well. Diamonds fall under the category of native minerals, and typically its colour is yellow, brown or grey to colourless. Moreover, the cleavage of this material is perfect in four directions, and the fracture is irregular. The mineral streak of a diamond is colourless. When considering the optical properties, diamond is isotropic.

Figure 01: Diamond

In this material, the carbon atoms are sp3 hybridized. Each atom forms a tetrahedral with another atom. The tetrahedral structures are rigid, and the bonds between atoms are very strong. Furthermore, diamond has the greatest number of atoms in a unit volume of the material.

What is Graphite?

Graphite is an allotrope of carbon having the hexagonal crystal structure. The compound naturally occurs as graphite ores; so, we can obtain this material through mining. It is the most stable allotrope of carbon at standard temperature and pressure. Moreover, under very high temperature and pressure conditions, graphite can convert into diamond. It has a high electrical conductivity.

Figure 02: Graphite

Graphite also falls under the category of native minerals. The colour may vary from iron-black to steel-grey. Furthermore, the cleavage of this material is basal, and the fracture is flaky. Hardness is very low, and it has a metallic, earthy lustre. The mineral streak of graphite is black. When considering the optical properties, the graphite is uniaxial.

What is Fullerene?

Fullerene is an allotrope of carbon which has a large spherical structure. The carbon atoms in this allotrope connect with each other via single and double bonds. Moreover, the spherical structure is a closed or partially closed mesh having fused rings containing 5 to 7 carbon atoms. They are sp2 hybridized atoms. However, the structure has an angle strain between atoms.

Figure 03: Structure of Fullerene Sphere

Furthermore, fullerenes are soluble in organic solvents, including toluene, chlorobenzene, etc. Generally, this material is an electrical insulator.

What is the Difference Between Diamond Graphite and Fullerene?

Diamond, graphite and fullerene are allotropes of carbon. The key difference between diamond graphite and fullerene is that diamond has a diamond cubic crystal structure and graphite has a hexagonal crystal structure, while fullerene occurs as a large spheroidal molecule. Furthermore, diamond is the hardest naturally occurring material on earth, but graphite and fullerene have comparatively low hardness.

Moreover, a further difference between diamond graphite and fullerene is that the carbon atoms of a diamond are sp3 hybridized but, in graphite and fullerene, they are sp2 hybridized. When considering the geometry around a carbon atom, in diamond, it is tetrahedral, and in graphite, it is a trigonal planar while, in fullerene, it is spherical.

Summary – Diamond vs Graphite vs Fullerene

Diamond, graphite and fullerene are allotropes of carbon. In summary, the key difference between diamond graphite and fullerene is that diamond has a diamond cubic crystal structure and graphite has a hexagonal crystal structure, while fullerene occurs as a large spheroidal molecule.