Gemstone profile and identification guide
Nigrine
Nigrine is an ambiguous term in gem trade usage and should be tied to tested mineral identity before strict species claims.
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Overview
Nigrine is an ambiguous term in gem trade usage and should be tied to tested mineral identity before strict species claims.
Did you know? Some historical gem names persisted in commerce despite inconsistent mineralogical usage.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Nigrine
Scientific classification: Historical/Trade Term (Ambiguous Species Usage)
Hardness: 6.5 Mohs
Transparency: opaque
Lustre: vitreous to submetallic
Crystal system: Species-dependent
Primary colour: Black
Secondary colour: Dark Brown Black
Colour family: Blacks
Instrument-based species confirmation is required due to term ambiguity.
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 conservative composition and treatment disclosures where needed.
Physical Properties
Hardness category: hard
Hardness value: 6.5 Mohs
Chemical composition: Species-dependent; term has been used inconsistently in trade contexts
Crystal system: Species-dependent
Common locations: Trade usage varies by seller and region
Learn more: Gem-A gemstone education resources.
Colour Variations
Dark gemstone trade term requiring explicit species confirmation.
Optical effects: None specified in the current dataset.
Detailed Gemology
Mineral species: Ambiguous trade term requiring species verification
Mineral group: Unresolved without testing
Chemical formula: Species-dependent; term has been used inconsistently in trade contexts
Mohs hardness: 6.5
Crystal system: Species-dependent
Lustre: vitreous to submetallic
Transparency: opaque
Streak: Variable
Cleavage: Variable
Fracture: Variable
Specific gravity: Variable
Refractive index: Variable
Optical phenomena: None typically diagnostic
Colour range: Dark brown-black to black
Common inclusions: Growth features, fractures, and matrix/inclusion structures as applicable
Geological environment: Species-dependent; see formation process
Principal mining regions: Trade usage varies by seller and region
Important commercial sources: Nigrine is treated as an ambiguous trade/historical term and not a single verified species label
Historical significance: Recognized in modern gem and mineral trade contexts.
Common treatments: Treatment practices vary by market and species; disclosure is required when present.
Synthetic or imitation forms: Potential imitations depend on actual marketed material.
Common look-alikes: Species-dependent look-alikes in trade.
Jewellery uses: Used in decorative dark-stone jewelry categories.
Care recommendations: Care should follow tested species identity rather than trade name alone.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Nigrine.
Formation
Depends on underlying identified species.
Origin
Nigrine is treated as an ambiguous trade/historical term and not a single verified species label
Uses
Best for: Used in decorative dark-stone jewelry categories.
Ideal uses: Entries where supplier testing details are available.
Care
Care should follow tested species identity rather than trade name alone.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Commonly confused gemstones
Nigrine FAQ
How can I identify Nigrine?
Compare hardness (6.5 Mohs), crystal system (Species-dependent), colour profile, and lustre (vitreous to submetallic) with your sample. Then cross-check related gemstones listed above.
What colour range does Nigrine appear in?
Dark gemstone trade term requiring explicit species confirmation.
Where is Nigrine commonly used?
Entries where supplier testing details are available.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 07 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 07 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 07 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 07 factual verification pass.