Grey to greyish black, metallically lustrous modification of carbon that forms hexagonal crystals. Graphite is the chemically most stable form of carbon. In an oxidizing atmosphere it remains stable up to around 550 °C, and displays high thermal and electrical conductivity. Its lamellar structure makes for low shear stress but high lubricity. To supplement dwindling natural reserves, graphite is synthesized as electrographite. Besides being supplied as powder, suspension and lubricating varnish, graphite also comes worked into pastes and self-lubricating materials (carbon face materials: Rotatherm^®; Statotherm^®; material for secondary seals.