Carbon Nanotube, a form of highly elongated fullerene, with a much smaller magcarbon nanotube alongside for comparison.
Any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube, as opposed to forms of carbon such as graphite or diamond which make extended networks that lead to crystals, or to amorphous forms of carbon such as soot. Spherical fullerenes are also known as buckyballs, and cylindrical fullerenes are known as carbon nanotubes or buckytubes.
Fullerenes were named after the early 1st century AT Old Earth thinker Buckminster Fuller, for the resemblance that a buckyball has to the geodesic domes he invented, since the carbon atoms form a series of hexagonal (sometimes pentagonal or heptagonal) rings. Since the Information Age, fullerenes have had a wide range of applications in materials science, electronics, and nanotechnology. The tensile strength of carbon nanotubes is an essential element in most megastructures, and fullerenes are a component in most varieties of diamondoid.