Graphite crystals. Coloured scanning electron micrograph (SEM) of graphite polyhedral crystals (GPCs) growing in a pore of glassy carbon (green). A rod-shaped crystal (purple) is seen, with two large polyhedral crystals (brown) behind it. 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 these highly ordered crystals. Larger GPCs could find applications in nanotechnology for their high electrical conductivity, strength and chemical stability. Magnification: x5900 at 6x7cm size.