Diamond

• Diamond has a strong covalent bond.
• Is very hard, the hardest natural substance.
• Very high melting and boiling point.
• Cannot conduct electricity, no free electrons to carry a charge.
• Diamond is the hardest known naturally occurring material. It has a giant covalent structure with each carbon bonded to four carbons in a regular tetrahedral lattice. The covalent bonds are very strong so require high energies to be broken, so the melting point is very high. It is a thermal electricity insulator because it does not have any charged particles (free electrons or ions) which are free to move.