Gemstone profile and identification guide
Turquoise has been used for ornament and status objects for millennia, yet its appeal remains straightforward: an unmistakable blue-to-green body colour, often paired with matrix patterns that make each piece visually individual.
Turquoise has been used for ornament and status objects for millennia, yet its appeal remains straightforward: an unmistakable blue-to-green body colour, often paired with matrix patterns that make each piece visually individual.
Did you know? Turquoise colour can shift toward green as iron becomes more influential and toward clearer blue where copper dominates.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Name: Turquoise
Scientific classification: Phosphate (Turquoise Group)
Hardness: 5.5 Mohs
Transparency: opaque
Lustre: waxy to subvitreous
Crystal system: Triclinic
Primary colour: Blue
Secondary colour: Cyan / Blue-Green
Colour family: Blues & Cyans
Look for opaque blue-green colour, a waxy to subvitreous lustre, and matrix that appears integrated with the stone rather than printed or superficial. It is commonly imitated, so texture and hardness matter.
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: medium
Hardness value: 5.5 Mohs
Chemical composition: Hydrated copper aluminum phosphate [CuAl6(PO4)4(OH)8.4H2O]
Crystal system: Triclinic
Common locations: Iran (Neyshabur), China (Hubei), United States (Southwest), Egypt (Sinai, historic)
Learn more: Gem-A gemstone education resources.
Turquoise sits in the blues & cyans grouping here, usually reading first as blue with cyan / blue-green appearing as a secondary note or modifier.
Optical effects: None specified in the current dataset.
Mineral species: Turquoise
Mineral group: Turquoise group
Chemical formula: Hydrated copper aluminum phosphate [CuAl6(PO4)4(OH)8.4H2O]
Mohs hardness: 5.5
Crystal system: Triclinic
Lustre: waxy to subvitreous
Transparency: opaque
Streak: White to bluish white
Cleavage: None to poor
Fracture: Conchoidal to uneven
Specific gravity: 2.60-2.90
Refractive index: 1.61-1.65
Optical phenomena: None commonly reported
Colour range: Blue, Cyan / Blue-Green, Teal, Turquoise, Green
Common inclusions: Matrix veining, porosity, and color zoning
Geological environment: Secondary copper-rich weathering zones in arid environments
Principal mining regions: Iran (Neyshabur), China (Hubei), United States (Southwest), Egypt (Sinai, historic)
Important commercial sources: Major commercial turquoise comes from China, Iran, and the southwestern United States
Historical significance: Turquoise has been used in jewelry and ritual objects for millennia.
Common treatments: Stabilization, impregnation, and dyeing are common and must be disclosed.
Synthetic or imitation forms: Reconstituted products and dyed howlite/magnesite imitations are common.
Common look-alikes: rhodonite, azurite, variscite
Jewellery uses: Turquoise is used chiefly for A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. In the trade it is commonly fashioned as cabochons, beads, carvings, and polished ornamental pieces, with Mohs hardness 5.5 guiding suitable jewellery applications.
Care recommendations: Avoid chemicals, heat, and prolonged exposure to water. Wipe gently with a soft cloth.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Turquoise.
Forms in arid regions when copper-rich solutions percolate through aluminum-rich rocks. Small differences in chemistry during growth can change colour, transparency, and crystal habit even within the same general formation setting.
Major commercial turquoise comes from China, Iran, and the southwestern United States
Best for: Turquoise is used chiefly for A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. In the trade it is commonly fashioned as cabochons, beads, carvings, and polished ornamental pieces, with Mohs hardness 5.5 guiding suitable jewellery applications.
Ideal uses: A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.
Avoid chemicals, heat, and prolonged exposure to water. Wipe gently with a soft cloth.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Compare hardness (5.5 Mohs), crystal system (Triclinic), colour profile, and lustre (waxy to subvitreous) with your sample. Then cross-check related gemstones listed above.
Turquoise sits in the blues & cyans grouping here, usually reading first as blue with cyan / blue-green appearing as a secondary note or modifier.
A good fit for collectors and jewellers looking for visible character without needing the highest hardness category.. 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.
