gemstone

Diamond (or Diamond Simulant)

Carbon (C) if diamond, various if simulant (e.g., Cubic Zirconia - ZrO2, Moissanite - SiC)

If diamond: Hardness 10, adamantine luster, cubic crystal system, perfect cleavage in 4 directions. If simulant, properties vary (e.g., CZ has hardness 8-8.5). Visible object is a faceted, colorless stone.

Identified July 10, 2026More gemstone →

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Physical properties

Formation & geological history

Natural diamonds form deep in the Earth's mantle under immense heat and pressure over billions of years, brought to the surface by volcanic pipes. Simulants are synthesized in laboratories.

Uses & applications

Used extensively in jewelry as gemstones. Industrial applications include cutting, drilling, and polishing tools due to extreme hardness (if true diamond).

Geological facts

Diamonds are the hardest known natural material on Earth. The optical properties (refractive index and dispersion) give faceted diamonds their brilliant sparkle.

Field identification & locations

Identification requires gemological testing (thermal conductivity, refractive index, magnification for inclusions). Often found in alluvial deposits or kimberlite pipes. Difficult to distinguish natural diamonds from synthetics or simulants by eye alone.

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