gemstone

Diamond (or Diamond Simulant)

Carbon (C) if diamond, various if simulant

If diamond: Hardness 10 (Mohs scale), colorless (in this image), adamantine luster, cubic crystal structure. If simulant (e.g. cubic zirconia): Hardness 8-8.5, colorless, vitreous to adamantine luster, cubic or diverse structure.

Identified July 10, 2026More gemstone →

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Physical properties

Formation & geological history

Natural diamonds form deep within the Earth's mantle under extreme heat and pressure over billions of years, brought to the surface by kimberlite eruptions. Synthetic diamonds are created in labs. Simulants like CZ are lab-grown.

Uses & applications

Predominantly used in jewelry due to extreme hardness and high dispersion. Also used extensively in industrial applications for cutting, grinding, and drilling.

Geological facts

Diamond is the hardest known natural material. Its brilliance is due to its high refractive index.

Field identification & locations

Identification requires gemological testing to distinguish between natural diamond, lab-grown diamond, and various simulants (CZ, moissanite, glass). Field identification involves observing brilliance, fire, and testing hardness or thermal conductivity.

Other gemstone specimens

See all

Cubic Zirconia (simulant) or Diamond

ZrO2 (Cubic Zirconia) or C (Diamond)

gemstone

Ammolite

Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)

mineral

Cubic Zirconia (or possibly Diamond)

Zirconium dioxide (or Carbon)

gemstone

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

sedimentary

Faceted Gemstone

Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass

gemstone

Milky Quartz

Silicon Dioxide (SiO2)

mineral