Where do you start with graphite? Do you begin at the beginning, when sedimentary carbon oxidizes during its transformation into metamorphic rock? Or do you look to the future where single-atom layers of graphite called graphene are used to transform everything from water filters to batteries? For us, graphite gets interesting around 4500 BCE, when the Boian culture in neolithic Europe began marking their pottery with geometric patterns in graphite. For the next six and a half millennia, humans have made marks with graphite, smearing it as powder, rubbing it as sticks, or casing it in wood to create perhaps the simplest and most versatile artistic instrument—the pencil.