Description and Identifying Characteristics of Graphite
Graphite's extreme softness, greasy feel, low specific gravity, and the ease with which it leaves dark grey to black marks on paper usually distinguish it from similar-looking metallic minerals. Its name comes from the Greek word 'graphein' ('to write'), a reflection of centuries of use in writing and drawing. Graphite is produced by metamorphosing organic material originally deposited as sediment or mixed with sediment. As organic material is metamorphosed, hydrogen and oxygen are driven off as water, leaving the carbon behind to form graphite. Well-formed graphite crystals are quite rare, and most graphite occurs in its massive form. It is a metallic mineral, black to dark grey, with a distinctive greasy feeling. As with many mineral properties, this greasy nature is a reflection of its internal crystal structure. On an atomic level, graphite has a sheet-like structure where carbon atoms lie in sheets that are only weakly bonded to the overlying and underlying carbon sheets. Strong chemical bonds, called covalent bonds, exist between the carbon atoms within each sheet, but the sheets are only held together by weaker surface attractions, called Van der Waals forces. Van der Waals forces are the same attractive forces that allow a gecko to climb smooth glass surfaces with its padded toes. They are easily broken forces, making massive graphite soft despite strong covalent bonds within its sheets.
Some of the world's greatest art was rendered in graphite, a mineral composed solely of carbon. Graphite is a dark grey to black, very soft, shiny metallic mineral with a distinctive greasy feeling. One of the Earth's softest minerals, graphite will easily leave marks on paper, which is why it is used for fine artist pencils. Even modern pencil 'lead' is composed of graphite mixed with clay. Paradoxically, even though graphite is soft enough for drawing and as a lubricant, it is also strong enough to refine furnaces and brake linings and create expensive lightweight sports equipment. Even more surprising, this versatile mineral was originally living organic material (usually plants) that was altered to form graphite as sedimentary deposits were metamorphosed. If you are looking for high quality, high purity and cost-effective graphite or require the latest price, please email contact mis-asia.