Black Graphite in Schist - 2 Pieces of Rock
Black Graphite in Schist, 2 Pieces
by American Scientific
Crystalline in form and the most stable form of carbon under standard conditions, Graphite is one of the allotropes of carbon, along with diamond and graphene. While it can be considered the highest grade of coal and just above anthracite, Graphite typically does not see use as fuel because it is difficult to ignite. It is a layered, planar structure, arranged into a honeycomb lattice. Each atom features covalent bonding, with only three of four electrons bonded, leaving the fourth to migrate through the plane and give it electrical conductivity.
It is most commonly seen as the "lead" in pencils, though it is chemically unrelated to the actual metal lead. Pencil lead is typically a mixture of powdered graphite and clay, and was invented in 1795 by Nicolas-Jacques Conté. Graphite finds many other uses, including in batteries, the brake linings of motor vehicles, as a lubricant in foundries, and as electrodes.