Over a long period of time while under extreme heat and pressure, graphite turns into which precious mineral?
Graphite and diamonds share a common characteristic. They are both pure carbon. What distinguishes the two is their molecular makeup. Graphite is composed of layers of molecules, whereas diamonds are cubic in nature. When subjected to high temperatures and incredible pressure, graphite molecules are forced to re-align and form a cubic formation known as crystal, and a diamond is born.
More Info:
en.wikipedia.org