Description
Diamond (Ancient Greek: ἀδάμας or adamas, "unbreakable") is an allotropic form of carbon that is found as a mineral but can also be produced in laboratories. In diamond, the carbon-carbon bonds have a tetrahedron structure, meaning the atoms are bound in three dimensions; this partly explains the hardness that gives the mineral its name. In contrast, graphite, the most common form of carbon on Earth, has a planar crystal structure, making it much softer and forming flaky layers. Diamond is the hardest known material found in nature and is therefore the benchmark for hardness 10 on the Mohs scale. Only a few industrially produced materials, also composed of pure carbon, are harder.
