DIAMOND.
What is diamond?
Diamond is the purest form of natural carbon. It occurs as small crystals embedded in rocks.
These are supposed to have been formed by the crystallization of carbon under extreme pressure and temperature in the interior of the earth.
THE PHYSICAL PROPERTIES OF DIAMOND.
Diamond
Has a very high melting point (almost 4000°C).
Very strong carbon-carbon covalent bonds have to be broken throughout the structure before melting occurs.
Is very hard.
This is again due to the need to break very strong covalent bonds operating in 3-dimensions.