Diamond

Diamond is a crystalline form of carbon in which each atom bonds to four neighbors in a rigid three-dimensional network. This structure gives it exceptional hardness and distinctive optical properties.

Diamond cubic: A crystal structure in which atoms form two interpenetrating face-centered cubic lattices. Diamond’s carbon atoms occupy this structure, linked by four covalent bonds each.
Carbon: A chemical element with atomic number 6 that forms the backbone of many molecules and solid materials. Diamond is one of carbon’s solid structural forms.
Diamond cutting: The shaping and polishing of diamond crystals into facets that control their appearance as gems. Facet geometry determines how effectively a gem returns light to an observer.
Mantle xenolith: A fragment of Earth’s mantle carried to the surface by rising magma. Some contain diamonds that provide evidence about conditions deep within Earth.
Covalent bond: A chemical bond formed when atoms share electron pairs. Shared electrons hold diamond’s carbon network together in three dimensions.
Allotropy: The existence of different structural forms of the same chemical element. Diamond and graphite are distinct arrangements of carbon atoms.
Abrasive: A hard material used to wear down, polish, or cut another surface. Diamond grit is used where ordinary abrasives cannot efficiently cut hard materials.
Kimberlite: A volatile-rich igneous rock that can transport mantle material, including diamonds, toward Earth’s surface. Many mined diamonds reach the surface in kimberlite pipes.
Mohs scale: A ranking of minerals by their resistance to scratching, from talc at 1 to diamond at 10. Diamond defines the scale’s top rank, though the scale does not measure absolute hardness.
Graphite: A carbon allotrope made of stacked sheets of strongly bonded atoms with weaker forces between sheets. Its layered structure contrasts with diamond’s rigid, three-dimensional bonding network.

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