Graphite stone stone was first exploited, as early as the 17th century, in the British mines of Seathwaite. Its first use was to make pencil leads. It was originally called, « leadagine », because of its resemblance to lead, which was then used for writing. It was not until 1779 that the Swedish chemist Carl Wilhelm Scheele analyzed it and discovered that it was in fact a crystalline form of carbon, and free of lead. The German geologist Abraham Gottlieb Werner gave it the name Graphite, issued from the Greek « graphein », meaning « to write ». This black, brittle mineral has been used for centuries for writing, from the manufacture of Indian ink to the most common household use of pencil. It is also used in industry in various forms. Indeed, it has numerous chemical and physical properties: high resistance to heat, low coefficient of thermal expansion, extremely low coefficient of friction, excellent conductor of heat and electricity, outstanding melting point at 3550°C…
AThus, it is used, among other things :
Electrodes, which are used in arc furnaces to melt scrap or steel, are mainly made of the synthetic version of this stone and account for 1/3 of world consumption. In medicine, it can be used as an absorbent in case of oral intoxication. It is also used in military to damage power plants, in the form of a bomb.
A soft and brittle mineral with a metallic lustre, graphite stone is a natural allotrope of carbon, just like diamond, chaoite and lonsdalcite. It has a greasy look and feel.
With a colour ranging from grey to black, its structure is composed of a superimposition of layers, called graphenes, themselves made up of a regular paving of hexagons, in a honeycomb pattern. These sheets are separated from each other by less than half a nanometre and are not very well bonded, which explains the mineral’s brittleness.
Graphite stone is a native element, found mainly in regional metamorphic sediments. Depending on the rocks, it can also be formed from organic coal, magma or by reduction of carbonates. It is also present in meteorites.
Natural graphite comes in three varieties :
Deposits can be found anywhere in the world; the main countries exploiting them are the United States, Mexico, China, Germany, Canada, Finland, Madagascar, Slovenia and Russia.
Natural stone is very present under the earth’s crust and, for this reason, there are no resource problems at present. However, with 73% of world production, China has a monopoly of natural stone and therefore controls the pricing. Because of the overabundance of minerals in its deposits, the country has, moreover, drastically reduced them. The price per tonne has been halved in just a few years. The country produces in quantity, but also in quality since its commodity has highly important carbon content (94 to 98%). It is thus positioned as the undeniable leading producer in the sector. Depending on demand, China can increase its output substantially, due to its huge reserves and the availability of cheap labour. It should be noted that this mineral is found in the composition of other stones, such as chiastolite, which contains cross inclusions, cliftonite, which is an ancillary variety, and pinolite, which is composed of white crystals of magnesite in a matrix of graphite and grey dolomite.
Synthetic graphite is generally produced using the Acheson process: it is obtained by graphitisation of a mixture of petroleum coke and precalcinated coal-tar pitch. During this high-temperature treatment (between 2,600 and 3,000°C), the carbon atoms reorganize into hexagonal crystal structures, like those of graphene, thus constituting the mineral in a synthetic version. It is purer than natural graphite stone nwith a carbon content of more than 99%, and offers better electrical conductivity as well as greater chemical resistance. Because of the long and expensive development process, the price of this type of stone is higher than the natural variety, ranging from $7,000 to $20,000 per tonne. The main producers are located in Germany, Switzerland, Japan and Great Britain.
Psychologically, graphite stone encourages communication and freedom of expression. It thus brings us self-confidence when speaking during a conference or a debate, clarifying ideas and thus the speech. Soothing, it allows a better control of our emotions and calls on us to take stock, with lucidity, when an ambiguous situation occurs. It gives restraint and a sense of diplomacy to people who are too spontaneous or too talkative, makes them take a step back and helps them to turn their tongue seven times in their mouth before speaking.
Spiritually, it is an anchor stone, whose preferred chakra is the Root chakra, or Muladhara. A base chakra, connected to Mother Earth, it is a source of well-being and security when energy flows harmoniously through it. On the vibratory level, this mineral is a shield against harmful energies, which it deflects towards the Earth. It is useful to neutralise the Hartmann’s knots.