Gemstone profile and identification guide
Blue Coral
Blue coral is generally a trade product category and often involves dyed or treated coral material.
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Overview
Blue coral is generally a trade product category and often involves dyed or treated coral material.
Did you know? Many coral products require legal and treatment documentation in responsible trade channels.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Blue Coral
Scientific classification: Organic Gem Material (Coral, frequently treated in blue products)
Hardness: 3.5 Mohs
Transparency: opaque
Lustre: waxy
Crystal system: Biogenic aggregate
Primary colour: Blue
Secondary colour: Blue Green
Colour family: Blues
Dye concentration in pores/channels and uniform vivid color can indicate treatment.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Trade-name entries include treatment/composition disclosures where applicable.
Physical Properties
Hardness category: soft
Hardness value: 3.5 Mohs
Chemical composition: Calcium carbonate with organic components
Crystal system: Biogenic aggregate
Common locations: Marine coral sources and treatment/manufacturing centers
Learn more: Gem-A gemstone education resources.
Colour Variations
Blue coral products in trade are often dyed or stabilized coral material.
Optical effects: None specified in the current dataset.
Detailed Gemology
Mineral species: Coral-based organic material
Mineral group: Organic gem material
Chemical formula: Calcium carbonate with organic components
Mohs hardness: 3.5
Crystal system: Biogenic aggregate
Lustre: waxy
Transparency: opaque
Streak: White
Cleavage: Not applicable
Fracture: Splintery to uneven
Specific gravity: 2.60-2.70
Refractive index: Variable spot values, often near 1.53 in coral materials
Optical phenomena: None typically diagnostic
Colour range: Blue to blue-green in treated trade products
Common inclusions: Growth channels, pores, organic structures
Geological environment: Marine biogenic growth environments
Principal mining regions: Marine coral sources and treatment/manufacturing centers
Important commercial sources: Blue coral in jewellery trade is commonly treated coral rather than naturally intense blue species-level material
Historical significance: Coral has longstanding ornamental use across cultures.
Common treatments: Dyeing, stabilization, and impregnation are common.
Synthetic or imitation forms: Dyed bone, plastic, and resin imitations are common.
Common look-alikes: Dyed howlite, dyed magnesite, plastic composites
Jewellery uses: Used in beads and decorative jewellery with treatment disclosure.
Care recommendations: Soft and porous; avoid chemicals, heat, and abrasive wear.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Blue Coral.
Formation
Coral skeleton is biogenic; blue trade color usually added or enhanced by treatment.
Origin
Blue coral in jewellery trade is commonly treated coral rather than naturally intense blue species-level material
Uses
Best for: Used in beads and decorative jewellery with treatment disclosure.
Ideal uses: Occasional-wear jewellery in protected settings.
Care
Soft and porous; avoid chemicals, heat, and abrasive wear.
Need another candidate? Use advanced gemstone search or return to the identification guide.
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Blue Coral FAQ
How can I identify Blue Coral?
Compare hardness (3.5 Mohs), crystal system (Biogenic aggregate), colour profile, and lustre (waxy) with your sample. Then cross-check related gemstones listed above.
What colour range does Blue Coral appear in?
Blue coral products in trade are often dyed or stabilized coral material.
Where is Blue Coral commonly used?
Occasional-wear jewellery in protected settings.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 05 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 05 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 05 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 05 factual verification pass.