Diamond

Did you know that pencil lead and diamonds are made of the same thing?  It is hard to believe but they are both made of carbon!  The carbon forms in different crystal types or shapes, which is why they are different.  Diamond is the hardest mineral, being a 10 on the Mohs hardness scale.  Diamonds are found in igneous rocks called Kimberlites, which are formed deep underground (between 90 and 280 miles below the surface of the Earth).  This photo shows cores of kimberlite rock from a drilling event.  Rock cores are stored in core boxes for examination.