Gemstone profile and identification guide
Sapphire covers far more than blue, yet the gem remains associated with crisp colour, durability, and a polished, highly wearable finish. Its place in jewellery owes as much to resilience as to appearance.
Sapphire covers far more than blue, yet the gem remains associated with crisp colour, durability, and a polished, highly wearable finish. Its place in jewellery owes as much to resilience as to appearance.
Did you know? Any gem-quality corundum that is not red is classified as sapphire, which is why the species covers a broad range of colours.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Name: Sapphire
Scientific classification: Oxide (Corundum Variety)
Hardness: 9 Mohs
Transparency: transparent
Lustre: vitreous to adamantine
Crystal system: Trigonal
Primary colour: Blue
Secondary colour: Sapphire Blue
Colour family: Blues & Cyans
Its high hardness and strong lustre help separate it from many blue, pink, yellow, and white alternatives. When comparing with spinel, topaz, or zircon, pay attention to durability and the corundum-like feel of the finish.
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity fields reviewed against consensus gemological references (GIA/Gem-A/Mindat/IGS).
Some market- and locality-level details may still require citation-grade source notes for publication workflows.
Hardness category: very hard
Hardness value: 9 Mohs
Chemical composition: Aluminum oxide (Al2O3)
Crystal system: Trigonal
Common locations: Sri Lanka, Madagascar, Australia, Myanmar, Kashmir (historic India)
Learn more: Gem-A gemstone education resources.
Sapphire sits in the blues & cyans grouping here, usually reading first as blue with sapphire blue appearing as a secondary note or modifier.
Optical effects: Asterism (in star sapphire), Colour Change (some sapphires)
Mineral species: Corundum (sapphire variety)
Mineral group: Corundum
Chemical formula: Aluminum oxide (Al2O3)
Mohs hardness: 9
Crystal system: Trigonal
Lustre: vitreous to adamantine
Transparency: transparent
Streak: White
Cleavage: No true cleavage; parting may occur
Fracture: Conchoidal to uneven
Specific gravity: 3.99-4.01
Refractive index: 1.76-1.77
Optical phenomena: Asterism (in star sapphire), Colour Change (some sapphires)
Colour range: Blue, Sapphire Blue, Pink
Common inclusions: Rutile silk, crystal inclusions, and healed fractures
Geological environment: Sapphire occurs in Metamorphic marbles and igneous/metamorphic deposits with alluvial concentrations. Its Trigonal structure reflects the pressure-temperature conditions of those host rocks, with notable occurrences in Sri Lanka, Madagascar, Australia, Myanmar, Kashmir (historic India).
Principal mining regions: Sri Lanka, Madagascar, Australia, Myanmar, Kashmir (historic India)
Important commercial sources: Commercial sapphire is sourced chiefly from Sri Lanka and Madagascar; Australia and Myanmar are also important
Historical significance: Ruby and sapphire are among the most historically significant and durable gem species.
Common treatments: Heat treatment is common; diffusion and fracture-filling treatments may occur and require disclosure.
Synthetic or imitation forms: Synthetic corundum (Verneuil, flux, hydrothermal) and glass imitations exist.
Common look-alikes: ruby, spinel, pink sapphire
Jewellery uses: Sapphire is used chiefly for Particularly useful where durability matters alongside colour, clarity, or optical performance.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 9 guiding suitable jewellery applications.
Care recommendations: Sapphire should be cleaned with lukewarm water, mild soap, and a soft brush. At Mohs 9 in the Trigonal system, avoid steam cleaners, harsh chemicals, and high-impact wear. Protect cleavage directions from sharp knocks during wear and setting.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Sapphire.
Sapphire is a Corundum (sapphire variety) material with chemistry Aluminum oxide (Al2O3). It develops in Metamorphic marbles and igneous/metamorphic deposits with alluvial concentrations, and economically significant production is associated with Sri Lanka, Madagascar, Australia, Myanmar, Kashmir (historic India).
Commercial sapphire is sourced chiefly from Sri Lanka and Madagascar; Australia and Myanmar are also important
Best for: Sapphire is used chiefly for Particularly useful where durability matters alongside colour, clarity, or optical performance.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 9 guiding suitable jewellery applications.
Ideal uses: Particularly useful where durability matters alongside colour, clarity, or optical performance.
Sapphire should be cleaned with lukewarm water, mild soap, and a soft brush. At Mohs 9 in the Trigonal system, avoid steam cleaners, harsh chemicals, and high-impact wear. Protect cleavage directions from sharp knocks during wear and setting.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Compare hardness (9 Mohs), crystal system (Trigonal), colour profile, and lustre (vitreous to adamantine) with your sample. Then cross-check related gemstones listed above.
Sapphire sits in the blues & cyans grouping here, usually reading first as blue with sapphire blue appearing as a secondary note or modifier.
Particularly useful where durability matters alongside colour, clarity, or optical performance.. For maintenance, follow the care guidance in this profile.
GIA: general gemstone identity (reviewed) - Reviewed as a direct core gemstone profile.
Gem-A: gemological education and terminology (reviewed) - Reviewed as a direct core gemstone profile.
Mindat: mineral species and locality index (reviewed) - Reviewed as a direct core gemstone profile.
International Gem Society: collector-facing gem reference (reviewed) - Reviewed as a direct core gemstone profile.
