Graphite

Graphite was named from the Greek "graphein" meaning 'to write' by German chemist and mineralogist A.G. Werner in 1789. It occurs most commonly in metamorphic rocks and is used as a lubricant, the manufacture of refractory crucibles and of course, pencils. It is easily distinguished by its greasy feel and the dark marks it leaves on hands.

Mineral Photos courtesy of R.Weller/Cochise College