On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral / gemstone variety · Natural identity; treatment status unknown
Fire Opal
A yellow, orange to red opal variety whose GB/T 16552-2017 Table A.2 basic name is "Fire Opal"; "fire" refers to the body color, not play-of-color. This page compares how the major standards and institutions name it, what must be disclosed when selling it, whether it can be worn every day, how it is treated and identified, and which source each conclusion comes from.
Price, rarity and origin are outside the scope of this wiki.
What this page can answer
This page covers
- How Fire Opal forms and what gives its colourFormation setting, process and timescale; where its colour and optical effects come from, each finding graded and sourced
- How to identify Fire OpalIdentification points from the research literature; how far lab testing can go
- Treatments and enhancements of Fire OpalThe enhancements and treatments the GB/T and JJA/AGL tables list
- Caring for and wearing Fire OpalCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of Fire OpalEach value with its source and check date
- Fire Opal in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Which of GIA, FTC, CIBJO and Gem-A have a name for it on record, and do those agree?
- Listing and disclosing Fire OpalThe listing name to use; what must be disclosed before sale
- Standard clauses that define Fire OpalWhich clause defines it, each cross-checked
What we cannot conclude
- Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.
- Geographic origin, unless an origin report accompanies the item.
- Price, rarity or investment value: this wiki covers naming and disclosure only.
Material research: formation, causes and history
What authoritative sources say about how this material forms, what causes its colour and optical effects, where its name comes from and how people have used it. Each statement carries an evidence grade and its sources; it describes the material in general, not any specific piece.
How it forms
Fire opal is a natural opal variety whose bodycolor is brown, yellow, orange or red. It frequently lacks play-of-color and is therefore often classed as a non-phenomenal opal; Mexican material, also called “Mexican opal,” is the only opal extracted in quantity that is clear enough to be faceted, its colour running from colorless to a dark red rivaling ruby. Unlike play-of-color, this bodycolor stems mainly from minute iron-bearing and other transition-metal-ion inclusions that absorb part of the visible spectrum selectively. Being an opal, it forms likewise from silica dissolved by rainwater, deposited in cracks and between layers of underground rock and consolidated as water is lost, and is hydrated amorphous silica.
Scope: Applies to the body colour and genesis of natural fire opal (including Mexican fire opal); does not apply to descriptions of precious opal showing play-of-colour.
Sources GIA Opal Description · G&G Fall 2013 · G&G Spring 2018
Where it forms
A formation setting like other sedimentary natural opal (silica-bearing groundwater depositing in rock cracks and between layers); Mexico is a major source
Sources GIA Opal Description
How it forms, step by step
Rainwater dissolves silica and carries it into underground rock; evaporation during dry periods deposits silica in cracks and between layers.
Sources GIA Opal Description
Minute iron-bearing and other transition-metal-ion inclusions are incorporated and selectively absorb part of the visible spectrum, giving a yellow, orange, brown, to red bodycolor.
Sources G&G Fall 2013
The material consolidates as it loses water into hydrated amorphous silica; fire opal usually lacks the ordered sphere stacking that yields play-of-color, so it often shows none.
Sources GIA Opal Description
Link to appearance
Fire opal’s appearance is dominated by bodycolor: iron-bearing and other inclusions absorb visible light to give yellow-to-red hues, while ordered-sphere diffraction is usually absent, so it is typically non-phenomenal.
Sources G&G Fall 2013
Timescale
The cited sources give no absolute timescale for fire opal formation.
Sources GIA Opal Description · G&G Fall 2013 · G&G Spring 2018
Supporting findings
Natural opal forms from silica dissolved by rainwater and deposited in cracks and between layers of underground rock; fire opal belongs to the same natural process.
Evidence grade AScope: General natural-opal formation; it omits fire-opal-specific stratigraphic detail.
Sources GIA Opal Description
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Wegel Tena, Wollo, Ethiopiaplay-of-color fire opal is described as rare there
Sources Gems & Gemology Summer 2010
North America
- Querétaro, Mexicospelled Querétero in GIA text
Sources GIA Gem Encyclopedia
- MexicoGIA notes fire opal is also called "Mexican opal"; the "only opal mined in quantity clear enough for faceting" remark is attributed by G&G to cutter Jürgen Schütz
Sources GIA Opal Description · G&G Spring 2018
- Opal Butte, Oregon, United Statesmost orange material reported unstable (crazes)
Sources Gems & Gemology Winter 1988
These are localities recorded by authoritative sources, not an origin finding for any individual piece. The CIBJO Gemstone Book (2022, §4.2.3) says a place of origin names where a gem was mined or harvested, is a matter of opinion, does not imply a level of quality, and that cutting, processing or exporting centres must not be used to imply origin. See how far testing can go on this page, the origin determination guide and the overview of recorded localities.
Causes of colour and optical effects
Fire opal’s yellow-to-brown bodycolor is mainly caused by iron-bearing and other transition-metal-ion inclusions absorbing part of the visible spectrum, not by play-of-color.
Evidence grade AScope: A general transition-metal-ion coloring statement using fire opal as the example; not every fire opal bodycolor has a single cause.
Sources G&G Fall 2013
When fire opal does show play-of-color, the physics matches that of precious opal: uniformly sized nanoscale silica spheres arranged in an orderly three-dimensional grating diffract white light into spectral colours that shift with the viewing angle, the sphere diameter setting the colour range (about 0.1 micron yields violet, about 0.2 micron red). The brown, yellow, orange or red bodycolour typical of fire opal instead arises from iron and other transition-metal impurities that take in certain wavelengths of visible light—a cause distinct from the diffracted flashes, which is why fire opal often shows none.
Evidence grade AScope: This mechanism applies to the play-of-color that fire opal may display and explains the optics only; it does not establish the locality, natural origin, or treatment status of any particular stone.
Sources GIA Opal Description · G&G Summer 2025
How it is identified
Fire opal looks similar to imitation or treated orange-red material, and appearance cannot reliably separate them. Identification is carried out in a laboratory, using composition and structure testing together with microscopy and instrumental analysis; the call should be issued by an accredited body and is not for the reader to make unaided.
Evidence grade AScope: Fire opal identification requires a professional laboratory, with the conclusion from an accredited body.
Other research findings
Fire opal is a transparent to translucent natural opal variety with a brown, yellow, orange, or red bodycolor; it often shows no play-of-color and is also known as “Mexican opal.”
Evidence grade AScope: A GIA descriptive definition; ‘often shows no play-of-color’ is a tendency, not absolute.
Sources GIA Opal Description
Among opals extracted in quantity, the Mexican “fire” opal alone is sufficiently clear to be faceted; its colour runs from colorless to a dark red rivaling ruby.
Evidence grade AScope: A market statement from a trade interview about Mexican fire opal’s facetability, not a global absolute.
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The cited sources give no systematic fire-opal-specific geology or locality data.
- ‘Often shows no play-of-color’ is a tendency; some fire opal may still show play-of-color.
Methodology
- Origin determination and its limits
- Quality grading and value factors
- How gemmology became a technical discipline
Evidence grades
- A
- Standards bodies, government geological surveys, peer-reviewed research and museum records
- B
- Institutional educational material
- C
- Specialist databases or cautious readings
A statement is never graded above its strongest source.
This section is LumaLark's own factual restatement of public authoritative sources, credited item by item; it contains no verbatim excerpts, images or third-party logos.
DecideListing name, disclosure, care and treatments
- Suggested listing name
- Fire Opal
GB/T 16552—2017 Table A.2 “Fire Opal” · IMA Mineral List 2026-07 “Opal”
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Filled / Fracture-filled (via parent material), Dyed (via parent material), Coated (via parent material)
Related:Disclosure and cautions
This page cannot answer
Natural? · Origin · Price
A lab report settles these; this wiki covers naming and disclosure.
Related:What this page can answer
Answer at a glance
Fire Opal is Yellow, orange to red opal variety; use "Fire Opal" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.2, row 火欧泊 (Fire Opal)
What this means for you
Before buying, check the recommended listing name "Fire Opal" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- Last reviewed
- 2026-09-01
Care and wear
Normal care for every gemstone (CIBJO Gemstone Book §6.1), in brief:
- Handle it gently.
- Store pieces apart when not worn, so they cannot scratch each other.
- Clean with warm soapy water and a soft brush.
- Use ultrasonic cleaners only with caution.
The §6.1 wording and the full list of §6.2 special-care letters cited on this page are on the general gem care page.
The item-by-item care advice that the GIA Care and Cleaning Guide gives for the whole class, and so for Fire Opal, is set out in full under care on the Opal entry.
Care
Fire Opal — care (special care): Untreated stones still need special care (SC)
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XII, Gemstone Information Chart, Opal Fire Opal N, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Treatments and identification leads
One row per treatment, with three standards side by side: how often it occurs and how stable it is (CIBJO), its category in GB/T 16552—2017 Table B.1 (this site's paraphrase) and how the JJA/AGL 2025 table lists it. Each CIBJO value links to its entry under “Testing and market”, where the wording and source are given in full.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Dyeing | — | — | Treatment | — | — |
| Coating | — | — | Treatment | — | — |
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Opal); JJA/AGL 2025
Whether a treatment has to show in the name differs between the two rule sets (this site’s paraphrase):
- GB/T 16552—2017: a method classed as treatment has to be stated in the name itself — the method put before the name, or added in brackets after it; a method classed as optimization does not need to appear in the name, though one marked “Optimization (annotation required)” still has to be noted in the quality documents. Source: §5.4.2.1 a), b); §5.4.2.2 a)
- CIBJO Gemstone Book 2022: no longer splits treatments into ones that need specific disclosure and ones that need only general disclosure: every treatment is to be disclosed, and the seller tells the buyer which treatment was used and what special care it calls for. Source: §4.2.5 Note 2, §4.2.5.1, pp.14–15
What this table covers
What this page can give
- Registered treatments, their stability and how often they occur (see the table above)
- Identification leads for each treatment, for use when sending a stone for testing
VerifyNames, standards, technical facts, clauses and sources
Names
Standard and listing namesThe Chinese formal name of Fire Opal comes from GB/T 16552—2017 Table A.2, and the suggested listing name is also Fire Opal. Names in four languagesThe four-language names are the Simplified and Traditional Chinese names, English Fire Opal and the Japanese name; the Japanese name is the entry's own, and GSJ's wording for this name is not yet verified by this site. Trade and mineralogical namesThe mineralogical name refers to a yellow, orange to red variety of opal. Institution usageFor authority wording, of GIA, FTC, CIBJO and Gem-A, this site records CIBJO's wording, with the material name written Fire Opal, based on the CIBJO Gemmological Laboratories Book 2024; CIBJO's is the only authority wording recorded here. The FTC text on file has no wording for this name (checked); GIA and Gem-A are unchecked. Bodies without a recorded wording show the entry's own English name, which does not represent their position.
- GSJ (Japan) formal name
- ファイアオパール (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 火欧泊 (GB/T 16552—2017 Table A.2)
- Mineralogical name
- Yellow, orange to red opal variety
Four-language names
- 简体中文
- 火欧泊
- 繁體中文
- 火歐泊
- English
- Fire Opal
- 日本語
- ファイアオパール
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Opal and natural amorphous silica materials
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Not applicable
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
GB/T Table B.1For Fire Opal, this site applies the Opal row of GB/T 16552—2017, Annex B, Table B.1: filling, graded according to the standard, with the grades explained on this site's Gem treatments page; dyeing, classed as treatment; coating, classed as treatment. What Table B.1 is is explained on this site's Gem treatments page. JJA/AGL designationsIn the table of principal gem names in the JJA/AGL (Japan) definitions and nomenclature of gems and ornamental materials, revised November 2025, Fire Opal is listed with the species opal and the colour orange to red; an untreated tier is listed, with the note play of colour. How to read the JJA/AGL table is explained on this site's Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Under the “Opal” row of Table B.1: Filling Graded — see §5.4.1, Table 1; Dyeing Treatment; Coating Treatment. The full row, with the effect column, is on the Opal page.
What Table B.1 is, and how the “see 5.4.1” grades are defined: see the GB/T 16552: optimization vs treatment page.
JJA/AGL (Japan) table of principal gem names, 2025
This table scrolls sideways on narrow screens.
| Gem name | Species | Colour | Listed in the table | Notes |
|---|---|---|---|---|
| Fire Opal | Opal | orange to red | an untreated tier is listed | play of colour |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.9
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
Among the registered material facts for Fire Opal, the composition (phase) is opal and the structure, registered under opal (the whole category), is amorphous; Mohs hardness is 5–6.5, and this site's qualifier states that the cited clause covers the whole species, of which fire opal is only one variety. Density, for opal as a whole category, is 1.25–2.23 g/cm³, which this site notes is derived from the clause value of 2.15 with an allowed deviation of +0.08/−0.90. The refractive index, for opal as a whole category, is 1.37–1.47, which this site notes is derived from the clause value of 1.450 with an allowed deviation of +0.020/−0.080, the clause also having finer sub-ranges, with the overall value taken; another registration gives a usual refractive index for fire opal of 1.42–1.43, noting that it can be as low as 1.37. Optically, for opal as a whole category, it is isotropic, and fire opal commonly shows anomalous extinction; transparency is transparent to translucent; the lustre, for opal as a whole category, is vitreous to resinous, treatment status untreated.
Registered material facts
Each row carries its own source and check date and can be cited on its own; “—” means the cited source gives no value, not “none”.
Chemical composition, luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for opal (whole class), so they are not repeated on the Fire Opal page; see the material facts on the Opal entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Fire Opal (how to read class-level values).
Definition
Fire Opal: opal with an orange, orange-red or red body colour.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 Colour · Fire opal (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Fire Opal — composition (phase): opal
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Fire Opal — structure (overall): amorphous (not crystalline)
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Fire Opal — Mohs hardness: 5–6.5
GIA Opal
Reference points on this site: Talc 1–3, Fluorite 4, Apatite 5–5.5, Orthoclase 6–6.5, Topaz 8, Diamond 10 (Source: GB/T 16553—2017); Gypsum 1.5–2, Calcite 3, Quartz 7 (Source: Handbook of Mineralogy); Corundum 9 (Source: GIA Gem Encyclopedia (care guide))
- Qualification
The clause we cite covers the whole species. This entry is only one variety of it.
Source & check 2026-09-20
- Source
- GIA Gem Encyclopedia — Opal (Gemological Institute of America): Section “FACTS”, “Mohs Hardness” (locator checked 2026-09-28)
- Fact checked on
- 2026-09-20
Fire Opal — cleavage: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Opal — stability: chips and cracks easily; porous, so keep it away from coloured liquids; will craze if it loses water, so keep it away from heat and dry air; avoid sudden temperature changes; no ultrasonic cleaning.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code b, special-care code c, special-care code d, special-care code e, special-care code j
- Treatment state
- untreated
Source & check 2026-09-21
- Source
- Fact checked on
- 2026-09-21
Physical properties
Fire Opal — density: 1.25–2.23 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
- Qualification
The clause we cite gives 2.15, with a stated tolerance of +0.08 / -0.90. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Fire Opal — optic character: isotropic; fire opal commonly shows anomalous extinction.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Opal — optic character: Anomalous extinction is common in fire opal
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 Optic character · Fire opal (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Fire Opal — refractive index: 1.37–1.47
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
- Qualification
The clause we cite gives 1.450, with a stated tolerance of +0.020 / -0.080. The range shown here is worked out from that.
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Fire Opal — refractive index: 1.42–1.43
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.42–1.43 as the usual value and notes that it can be as low as 1.37.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 Refractive index · Fire opal (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Fire Opal — birefringence: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Fire Opal — transparency: transparent to translucent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Fire Opal — pleochroism: none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Opal — fluorescence (overall): none to moderate, green-brown; may be phosphorescent.
GB/T 16553—2017
UV fluorescencegreen-brownnone–moderateDots are illustrative colours built from the colour names, not measured values
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 Fluorescence (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
optical effect (play of colour)2 sources compared
Fire Opal — optical effect (play of colour): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Opal — optical effect (play of colour): play-of-colour.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Fire Opal — optical effect (chatoyancy): seen; rare
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Opal — body colour: Yellow, red, or orange to brown body colour, with or without play-of-colour.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Hessonite, Malaya Garnet, Mali Garnet and other entries also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
- CIBJO definitions
- play of colour, chatoyancy
Quality factors
Fire Opal — quality factor (lustre): vitreous to resinous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- opal (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
This material (RI / SG midpoints): 1.42 / 1.74; Closest values: 1Synthetic Opal 1.45 / 2.08, 2Mammoth Ivory 1.53 / 1.75, 3Ivory 1.535 / 1.85, 4Hackmanite 1.483 / 2.27, 5Chrysocolla 1.516 / 2.2
Show the full chart (330 registered materials)
Outside the full chart's range, drawn as triangles at the edge (RI / SG midpoints): Hematite 3.045/5.12, Synthetic Rutile 2.76/4.26, Rutile 2.753/4.23, Synthetic Moissanite 2.67/3.22
Testing and market
The CIBJO laboratory protocol covers Fire Opal under “Opal” (§6.1.56): see identification on the Opal entry; the required tests are listed on the CIBJO laboratory protocol table for Opal.
How far testing can go
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Fire Opal has a clause-level definition in the gem materials list of CIBJO Gemmological Laboratories Book 2024 under the entry name Fire opal; the definition records the mineral species as opal and the mineral/gem variety as fire opal, with the CIBJO wording quoted in full under Clause-level definitions on this page. The cross-check result is that it is defined directly by CIBJO and also appears in the GB/T annex.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Fire opal | 7.2.1.89 | Yellow, red, or orange to brown body colour, with or without play-of-colour, transparent to translucent | Defined directly by CIBJO; also present in the GB/T annex. |
Evidence and sources
Authority basis and clause sources
Sources
- CIBJO – The World Jewellery Confederation. Gemmological Laboratories Book (Blue Book), Gemmological Commission 2024-1.
- CIBJO – The World Jewellery Confederation. The Gemstone Book (Blue Book), 2022.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- RRUFF Project, in partnership with the IMA – International Mineralogical Association. IMA Mineral List.
- Geological Survey of Japan, AIST (Japan). Museum mineral specimens, browse by classification.
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
Related-entry tree for Opal on this site: 17 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Fire Opal) is marked.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Opal and natural amorphous silica materials | Live |
| Treatments recorded for this material | Filled / Fracture-filled (via parent material), Dyed (via parent material), Coated (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Fire Opal entry are maintained by the LumaLark wiki and matched one by one to the standard clauses or institutional sources they cite: every fact carries its source (with a clause or page locator) and a check date, so it can be traced back to the original; clause-level definitions also carry a cross-check result. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.