Diamond

Diamond is a form of carbon in which each carbon atom is covalently bonded to four other carbon atoms. Covalent bonds are formed when atoms share electrons. In diamond, these bonds join the atoms into a giant three-dimensional lattice: a continuous network extending throughout the structure.

The arrangement of atoms and bonds explains diamond’s properties:

• Extreme hardness: the strong covalent bonds lock the carbon atoms into a rigid network, making the structure difficult to deform.
• Very high melting point: a large amount of energy is needed to break the many strong covalent bonds throughout the lattice.
• No electrical conductivity: all the outer electrons of each carbon atom are used in covalent bonds. There are no delocalised electrons or other charged particles free to move through the structure and carry charge.