Graphite (5) Raw Minerals Stones Rocks Collecting

Description

Origin : Italy (Piemonte)

Graphite 71-100 gr - cm 7-10 Raw Minerals Stones Rocks for Collection.

Graphite is a mineral that represents one of the allotropic states of carbon.
It is an excellent electrical conductor and is the material with the highest melting temperature (3,500 ° C).
Graphite has been known since the 18th century: it was called "plumbago", "Molibdaena" or "black lead" referring to lead and molybdenum, actually absent in its chemical composition. It is also called "painters' mica", both for its lamellar appearance and for the characteristic of leaving traces on paper: in fact its name derives from the Greek γράφω (graph) which means "I write".
Graphite is found in lamellar crystals: leaf masses or scattered laminettes of opaque black color, sometimes with hexagonal contours and with dense streaks.
Structurally, the carbon atoms form a layered hexagonal lattice, with σ and π bonds within each layer, while several layers are held together by Van der Waals forces.
Graphite has metamorphic origin, the result of the same long natural process from which fossil carbons are born. In practice we are in the presence of plant remains and carbon which, due to the pressure of the sediments (lower than that which gives rise to diamonds) and a given temperature (between 1500 and 3000 degrees centigrade) become, after a long process, graphite.
Large deposits can be found in Sri Lanka, Madagascar, Russia, South Korea, Mexico and other Eastern European countries. In Italy, profits are found in Val Chisone (Piedmont); in modest aggregates also in Val Bormida (Liguria) and in Calabria.
Graphite is used to make pencils, refractory material, lubricants, dyes and electrodes for EDM.
It was also used in the RBMK 1000 nuclear reactors as a neutron moderator, in the form of bars to absorb the radiation emitted by the bars above (usually of plutonium).
Two-dimensional sheets of graphite called graphene were used to make the smallest transistors produced in the world. Some researchers believe that in the near future they could replace silicon, as the basis for the development of transistors. In September 2021, the first series production of an electric car with a graphene battery will start.