Diamond is a single element, carbon, with every atom bonded to four neighbors in a cubic crystal. It is the hardest gem, Mohs 10.
In more detail
Its refractive index is 2.417, its dispersion 0.044 and its specific gravity 3.52. It is singly refractive. It can be natural or laboratory-grown; both are diamond.
Related terms
- Natural diamond: A natural diamond is a diamond that formed in the earth, about 160 km deep, under enormous heat and pressure. An eruption carried it to the surface.
- Laboratory-grown diamond: A laboratory-grown diamond is a diamond that people grow with machines, by HPHT or CVD. It has essentially the same composition, crystal structure and properties as a natural diamond.
- Moissanite: Moissanite is silicon carbide, one silicon atom for every carbon atom, in a hexagonal crystal. It is a diamond simulant, and every moissanite in jewelry is laboratory-grown.
- Simulant: A simulant is a material that looks like a gem but has a different chemistry, structure and properties. Cubic zirconia, moissanite and glass are diamond simulants.
- Refractive index: Refractive index is the speed of light in a vacuum divided by its speed in the stone. A higher index bends light more where it crosses a surface at an angle.