mineral

Ruby

Corundum (Al2O3 with Chromium trace)

Hardness: 9.0 on Mohs scale; Color: Red to deep pinkish-red; Luster: Vitreous to adamantine; Crystal structure: Trigonal/Hexagonal; Cleavage: None (has parting); Specific gravity: 3.97–4.05

Hardness: 9
Color: Red to deep pinkish-red
Luster: Vitreous to adamantine

Identified May 24, 2026More mineral →

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Physical properties

Hardness: 9.0 on Mohs scale; Color: Red to deep pinkish-red; Luster: Vitreous to adamantine; Crystal structure: Trigonal/Hexagonal; Cleavage: None (has parting); Specific gravity: 3.97–4.05

Formation & geological history

Formed through contact metamorphism or in igneous environments. Usually found in marble or as alluvial deposits. Many record-breaking rubies originate from the Mogok region of Myanmar, formed millions of years ago during the Himalayan orogeny.

Uses & applications

Primary use in high-end jewelry and gemstone collecting. Synthetic rubies are used in industrial lasers, watch bearings, and precision instruments.

Geological facts

The specific specimen in the image is likely the 'Burj Alhamal' ruby, which was unveiled in Dubai; it is one of the largest rough rubies ever found, weighing over 8,400 carats. Rubies are the hardest natural gemstone after diamonds.

Field identification & locations

Identify by its intense 'pigeon blood' red color and extreme hardness (will scratch glass easily). In the field, look for hexagonal crystal shapes in host marble or search river gravels (placers) in known ruby-bearing regions like Myanmar, Mozambique, or Sri Lanka.