Gemstone profile and identification guide
Pinfire Opal
Pinfire opal is a pattern descriptor for precious opal with fine pinpoint color flashes.
Profile Navigation
Overview
Pinfire opal is a pattern descriptor for precious opal with fine pinpoint color flashes.
Did you know? Pattern type is a key quality descriptor in opal valuation alongside brightness and color.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Pinfire Opal
Scientific classification: Mineraloid (Precious Opal Pattern Descriptor)
Hardness: 5.75 Mohs
Transparency: translucent
Lustre: waxy to vitreous
Crystal system: Amorphous
Primary colour: Multicolor Pinpoint Flashes
Secondary colour: White
Colour family: Multi
Fine dot-like play-of-color mosaic identifies pinfire pattern class.
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: medium
Hardness value: 5.75 Mohs
Chemical composition: Hydrated silica (SiO2.nH2O)
Crystal system: Amorphous
Common locations: Australia, Ethiopia, Mexico
Learn more: Gem-A gemstone education resources.
Colour Variations
Precious opal showing tiny pin-point play-of-color sparks called pinfire pattern.
Optical effects: Play of Color (Pinfire Pattern)
Detailed Gemology
Mineral species: Opal (pattern-grade descriptor)
Mineral group: Opal mineraloid
Chemical formula: Hydrated silica (SiO2.nH2O)
Mohs hardness: 5.75
Crystal system: Amorphous
Lustre: waxy to vitreous
Transparency: translucent
Streak: White
Cleavage: None
Fracture: Conchoidal to uneven
Specific gravity: 1.98-2.25
Refractive index: 1.37-1.52
Optical phenomena: Play of color, pinfire pattern
Colour range: Multicolor pinpoints over light or dark body tones
Common inclusions: Growth features, fractures, and matrix/inclusion structures as applicable
Geological environment: Species-dependent; see formation process
Principal mining regions: Australia, Ethiopia, Mexico
Important commercial sources: Pinfire describes opal play-of-color pattern, not a separate opal species
Historical significance: Recognized in modern gem and mineral trade contexts.
Common treatments: Treatment status varies by product; disclosure recommended.
Synthetic or imitation forms: Imitations may exist depending on material category.
Common look-alikes: Species-dependent look-alikes in trade.
Jewellery uses: Pinfire Opal is used chiefly for Protected opal settings and collector pieces.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 5.75 guiding suitable jewellery applications.
Care recommendations: Protect from dehydration and thermal shock; avoid ultrasonic cleaners.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Pinfire Opal.
Formation
Forms from hydrated silica sphere structures that diffract light.
Origin
Pinfire describes opal play-of-color pattern, not a separate opal species
Uses
Best for: Pinfire Opal is used chiefly for Protected opal settings and collector pieces.. In the trade it is commonly fashioned as faceted stones, calibrated cuts, and higher-clarity collector pieces, with Mohs hardness 5.75 guiding suitable jewellery applications.
Ideal uses: Protected opal settings and collector pieces.
Care
Protect from dehydration and thermal shock; avoid ultrasonic cleaners.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Gemstones from the same mineral family
Commonly confused gemstones
Pinfire Opal FAQ
How can I identify Pinfire Opal?
Compare hardness (5.75 Mohs), crystal system (Amorphous), colour profile, and lustre (waxy to vitreous) with your sample. Then cross-check related gemstones listed above.
What colour range does Pinfire Opal appear in?
Precious opal showing tiny pin-point play-of-color sparks called pinfire pattern.
Where is Pinfire Opal commonly used?
Protected opal settings and collector pieces.. 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.