Graphite
Mineral graphite is one of alotrop carbon. It was named by Abraham Gottlob Werner in 1789 from the Greek word γραφειν: "drawing / writing", because of its use in pencil. In contrast to diamonds, graphite is a semi-metallic electric conductor, and can be used, for example, in arc lamp electrodes. Graphite holds respect as the most stable form of carbon under standard temperature and pressure. Therefore, it is used in thermochemistry as a standard condition to define the heat of forming carbon compounds. Graphite can be considered the highest grade of coal, just slightly above the anthracite and therefore also called meta-anthracite, although it is rarely used as fuel because it is difficult to ignite.