Graphite (/ˈɡræfaɪt/), archaically referred to as plumbago, is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure. It occurs naturally in this form and is the most stable form of carbon under standard conditions. Under high pressures and temperatures it converts to diamond. Graphite is used in pencils and lubricants. It is a good conductor of heat and electricity. Its high conductivity makes it useful in electronic products such as electrodes, batteries, and somarksReferencColorIron-black to steel-gray; deep blue in transmitted lightCrystal habitTabular, six-sided foliated masses, granular to compacted massesTwinningPresentCleavageBasal – perfect on {0001}FractureFlaky, otherwise rough when not on cleavageTenacityFlexible non-elastic, sectileMohs scale hardness1–2LusterMetallic, earthyStreakBlackDiaphaneityOpaque, transparent only in extremely thin flakesSpecific gravity1.9–2.3Density2.09–2.23 g/cm3Optical propertiesUniaxial (–)PleochroismStrongSolubilitySoluble in molten nickel, warm chlorosulfuric acid[1]Other characteristicsstrongly anisotropic, conducts electricity, greasy feel, readily marks