mineral

Rough Diamond (or Quartz Crystal)

Carbon (C) [if Diamond] / Silicon Dioxide (SiO2) [if Quartz]

Hardness: 10 on Mohs scale (Diamond) or 7 (Quartz). Colorless to transparent with high adamantine or vitreous luster. Trigonal or cubic crystal habits. Specific gravity: 3.52 (Diamond) vs 2.65 (Quartz).

Hardness: 10 on Mohs scale (Diamond) or 7 (Quartz)

Identified July 22, 2026More mineral →

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Physical properties

Formation & geological history

Diamonds form deep within the Earth's mantle under extreme pressure and temperature before being brought to the surface via kimberlite eruptions. Quartz forms in igneous, metamorphic, and sedimentary environments from silica-rich fluids.

Uses & applications

Diamonds are valuable gemstones used in high-end jewelry and industrial cutting, drilling, and polishing tools. Quartz is used in electronics, glassmaking, and mineral collections.

Geological facts

Rough diamonds often have a greasy luster or octahedral crystal faces. Small clear pebbles found in alluvial deposits are frequently mistaken for diamonds when they are actually clear quartz or topaz.

Field identification & locations

Can be identified by extreme hardness (scratches all other minerals) and thermal conductivity test. Commonly found in Kimberlite pipes in Africa, Russia, Australia, and Brazil, as well as stream gravels.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

sedimentary

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

mineral

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock