---
title: "Diamond: meaning in gemology"
description: "Diamond is a single element, carbon, with every atom bonded to four neighbors in a cubic crystal. It is the hardest gem, Mohs 10."
url: https://digitalgemology.com/learn/glossary/diamond
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

> Markdown copy of https://digitalgemology.com/learn/glossary/diamond. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons.
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[Glossary](https://digitalgemology.com/learn/glossary) · Diamond and simulants

# Diamond

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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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.

## Learn more

- [Diamond vs moissanite: two look-alikes, two different materials](https://digitalgemology.com/learn/diamond-vs-moissanite/diamond-vs-moissanite-differences)
- [Diamond vs moissanite properties: hardness, refractive index, dispersion, density](https://digitalgemology.com/learn/diamond-vs-moissanite/diamond-vs-moissanite-properties)
- [Diamond 3D models and cutting files](https://digitalgemology.com/gemstones/diamond)

[All 328 terms](https://digitalgemology.com/learn/glossary)