Gemstone profile and identification guide
White Opal
White opal is opal with light body tone, occurring as common or precious opal types.
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Overview
White opal is opal with light body tone, occurring as common or precious opal types.
Did you know? Not all white opal shows strong play-of-color; common opal lacks diffraction fire.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: White Opal
Scientific classification: Mineraloid (Opal Variety)
Hardness: 5.75 Mohs
Transparency: translucent
Lustre: waxy to vitreous
Crystal system: Amorphous
Primary colour: White
Secondary colour: Play of Color
Colour family: Whites & Neutrals
Body tone and play-of-color quality determine white opal classification in trade.
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 and treatment-sensitive entries include explicit disclosure language where applicable.
Physical Properties
Hardness category: medium
Hardness value: 5.75 Mohs
Chemical composition: Hydrated silica (SiO2.nH2O)
Crystal system: Amorphous
Common locations: Australia, Ethiopia, Mexico, Brazil
Learn more: Gem-A gemstone education resources.
Colour Variations
White to milky opal body with variable play-of-color depending on quality.
Optical effects: Play of Color (in precious material)
Detailed Gemology
Mineral species: Opal
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: None typically diagnostic
Colour range: White/milky body with variable spectral flashes
Common inclusions: Species-dependent inclusions and growth features
Geological environment: Species-dependent
Principal mining regions: Australia, Ethiopia, Mexico, Brazil
Important commercial sources: White opal is a standard opal body-tone category from major opal-producing localities
Historical significance: Recognized in gemological and lapidary trade.
Common treatments: Treatment status varies by product; disclose when present.
Synthetic or imitation forms: Imitations may exist depending on species.
Common look-alikes: Species-dependent look-alikes.
Jewellery uses: Used in cabochons and fine opal jewelry.
Care recommendations: Protect from dehydration and thermal shock; avoid ultrasonic cleaning.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for White Opal.
Formation
Forms through low-temperature silica deposition in host rock voids and fractures.
Origin
White opal is a standard opal body-tone category from major opal-producing localities
Uses
Best for: Used in cabochons and fine opal jewelry.
Ideal uses: Light-bodied opal jewelry in protected settings.
Care
Protect from dehydration and thermal shock; avoid ultrasonic cleaning.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Commonly confused gemstones
White Opal FAQ
How can I identify White 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 White Opal appear in?
White to milky opal body with variable play-of-color depending on quality.
Where is White Opal commonly used?
Light-bodied opal jewelry in protected settings.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 09 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 09 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 09 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 09 factual verification pass.