gemstone

Uncut diamond (likely gemstone)

Diamond — crystalline carbon, C

AI-generated identification · may be incorrect

Mohs hardness 10; typically colorless to pale gray, adamantine luster, cubic crystal structure, no cleavage visible in this image, and specific gravity about 3.52. The rough, strongly reflective, angular appearance is consistent with diamond, though the photograph cannot confirm identity.

Identified August 19, 2026More gemstone →

Explore Uncut diamond (likely gemstone) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms deep in Earth’s mantle under extreme pressure and temperature, commonly older than 1 billion years, then reaches the surface in kimberlite or lamproite volcanic pipes and alluvial deposits.

Uses & applications

Used primarily in jewelry and cutting tools; gem value depends on verified carat weight, color, clarity, cut potential, and laboratory certification.

Geological facts

Diamond is the hardest natural mineral but can chip along its four cleavage directions. Many rough-looking clear stones are imitations such as cubic zirconia, quartz, or glass.

Field identification & locations

Field clues include exceptional brilliance, strong thermal conductivity, and lack of scratching by quartz; definitive identification requires refractive-index, thermal-conductivity, or spectroscopy testing. Major sources include Botswana, South Africa, Russia, Canada, and Australia.