atomic number 6

fullerene - a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms

chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter

carbon 14, radiocarbon - a radioactive isotope of carbon

char - a charred substance

charcoal, wood coal - a carbonaceous material obtained by heating wood or other organic matter in the absence of air

carbon black, crock, lampblack, smut, soot - a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink

activated carbon, activated charcoal - powdered or granular carbon used for purifying by adsorption; given orally (as a slurry) it is an antidote for some kinds of poisons

black lead, graphite, plumbago - used as a lubricant and as a moderator in nuclear reactors

coal - fossil fuel consisting of carbonized vegetable matter deposited in the Carboniferous period

adamant, diamond - very hard native crystalline carbon valued as a gem

limestone - a sedimentary rock consisting mainly of calcium that was deposited by the remains of marine animals

crude, crude oil, fossil oil, petroleum, rock oil, oil - a dark oil consisting mainly of hydrocarbons