Lavoisier noted the overall weight of the jar was unchanged and that when it burned, the diamond had combined with oxygen to form carbon dioxide.
He concluded that diamond and charcoal were made of the same element – carbon.
Although crystalline nanotubes have been observed, they are generally amorphous.
The structures of eight allotropes are shown at the bottom of this page.
Carbon has been known since ancient times in the form of soot, charcoal, graphite and diamonds.
Ancient cultures did not realize, of course, that these substances were different forms of the same element French scientist Antoine Lavoisier named carbon and he carried out a variety of experiments to reveal its nature.
Carbon has the highest melting/sublimation point of all the elements and, in the form of diamond, has the highest thermal conductivity of any element.Graphite is used for pencil tips, high temperature crucibles, dry cells, electrodes and as a lubricant.Diamonds are used in jewelry and – because they are so hard – in industry for cutting, drilling, grinding, and polishing.Note: At normal atmospheric pressure, carbon does not melt when heated, it sublimes. it undergoes a phase change directly from solid to gas.If the pressure is increased to 10 atmospheres carbon (graphite) is observed to melt at 3550 °C.