Why are some properties of diamond different from those of graphite?

1 Answer
Dec 1, 2016

Diamonds have a tetrahedral-like composition while graphite has a hexagonal-like arrangement layered in sheets.


Diamonds and graphite are both allotropes of Carbon.

Allotropes are compounds of the same composition, but exists in two or more different forms due to the different bonding.

Carbon is a very common example because of how identifiable it is, most commonly diamonds and graphite.

Diamonds form when the carbon atoms are bonded together in a tetrahedral-like lattice arrangement. This is the result of high temperature and pressure at the same time over a long period of time, deep in the Earth's mantle.

It's because the carbon atoms are rearranged in a specific geometric shape that gives the diamond its properties. This results in a diamond's hardness, extraordinary strength and durability. In addition, because of its tetrahedral-like structure, diamonds are practically resistant to compression.

Graphite however, is when the carbon atoms bond together in sheets - hexagonal-like lattice. Graphite is formed from the carbon atoms resulting from the metamorphism of minerals such as marble, quartz, etc. The arrangement of the molecules are a result of a different physical structure.

Graphite's structure of sheets are soft because of its intermolecular forces. Being incredibly weak, the graphite's properties (mainly softness) are a result of the strength of the force.

Hope this helps :)