gemstone

Diamond (or Simulant)

Carbon (C) or various simulants (e.g., Cubic Zirconia)

Assuming diamond: Hardness 10 (Mohs), colorless to various colors, adamantine luster, isometric crystal structure, perfect octahedral cleavage, specific gravity 3.52. If simulant (e.g. CZ): Hardness 8-8.5, colorless, vitreous to subadamantine luster, isometric structure.

Identified July 10, 2026More gemstone →

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Physical properties

Formation & geological history

Natural diamonds form deep in the Earth's mantle under high pressure and temperature over billions of years, brought to the surface by kimberlite or lamproite volcanic pipes. Simulants are often lab-grown.

Uses & applications

Used extensively in jewelry (rings, necklaces, earrings) and in industry for cutting, grinding, and polishing tools due to its extreme hardness.

Geological facts

Diamond is the hardest known natural material on Earth. The name originates from the ancient Greek word 'adamas', meaning 'unalterable' or 'unbreakable'.

Field identification & locations

True diamonds can be identified by their high refractive index, dispersion (fire), and extreme hardness. Identifying natural vs. lab-grown or simulant often requires specialized gemological equipment.

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