Graphite crystals. Coloured scanning electron micrograph (SEM) of graphite polyhedral crystals (GPCs, purple) growing in a pore of glassy carbon. Rod-shaped crystals and nanotubes (green) are also seen. These crystals are an unusual form of carbon, found in the pores of industrial glassy carbon, grown under hydrothermal conditions of high temperature and pressure. Extremely thin, needle-like carbon nanotubes develop into the highly ordered crystals. Larger GPCs could find applications in nanotechnology for their high electrical conductivity, strength and chemical stability. Magnification: x5800 at 6x7cm size.