On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Commercial / trade name · Natural identity; treatment status unknown
Fire Agate
A mostly opaque agate that shows iridescence over a brown body color. It is a chalcedony (quartz) material, not the same material as the orange-red Fire Opal. 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 Agate 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 AgateIdentification points from the research literature; how far lab testing can go and whether a synthetic exists
- Hardness, density and refractive index of Fire AgateEach value with its source and check date
- Fire Agate in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Has any of GIA, FTC, CIBJO or Gem-A put a name for it on record here?
- Listing and disclosing Fire AgateThe listing name to use; what must be disclosed before sale
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 agate is a variety of agate (chalcedony, cryptocrystalline quartz): an iridescent 'fire' shows against a brown body colour, so the material is not an independent mineral species but an iron-bearing, silica (chalcedony) substance. It forms as other agates do — silica-bearing hydrothermal fluids fill fractures in the host rock (a volcanic rock) and deposit silica in repeated cycles. Work on Deer Creek fire agate (Arizona) ties the fire effect to the particular morphology of a chalcedony that is poorly ordered (crystallinity index 0.1–1.5) and carries a colloform texture, being low-order chalcedony mixed with mogánite (6.6% on average), micro-quartz and opal-C; the multi-layered spheroidal (bubble-like) silica bodies visible in hand specimens may act as centres where white light is reflected and interferes. Scattered pigment within the silica matrix — minute iron oxides, namely magnetite and maghemite, plus titanium oxides, rutile and anatase — accounts for its red-brown body colour.
Scope: Applies to explaining the identity of fire agate as a chalcedonic agate variety, its fire mechanism and colouration, and its origin as an infilling of fractures in volcanic rock; not applicable to determining the specific locality, treatment or value from the name.
Sources G&G Fall 2013 · Journal article (Deer Creek fire agate)
Where it forms
Fractures/veins in volcanic host rock: silica minerals fill fractures and precipitate cyclically.
Sources G&G Fall 2013 · Journal article (Deer Creek fire agate)
(For comparison) agates commonly form in gas cavities of volcanic rocks, filling from the wall inward.
Sources G&G Fall 2013 · Journal article (Deer Creek fire agate)
How it forms, step by step
Silica-bearing fluids are supplied along fractures/cavities in the host rock.
Sources Journal article (Deer Creek fire agate)
The fluids vary cyclically and precipitate silica phases such as poorly ordered chalcedony, micro-quartz and opal-C.
Sources Journal article (Deer Creek fire agate)
Iron and titanium oxide pigments scatter within the silica matrix to produce the red-brown colour; the colloform structure produces the fire effect.
Sources Journal article (Deer Creek fire agate)
Link to appearance
It shows iridescent fire on a brown body colour; but appearance cannot substitute for identification of the material (chalcedony) and any treatment/imitation.
Sources G&G Fall 2013 · Journal article (Deer Creek fire agate)
Timescale
The cited sources give no absolute age or growth duration for fire agate.
Sources G&G Fall 2013 · Journal article (Deer Creek fire agate)
Related base materials
- Chalcedony (cryptocrystalline quartz): Host material (agate is banded chalcedony)
- Quartz (SiO2): Host mineral composition
Supporting findings
Fire agate's silica fills fractures in its volcanic host rock, deposited from silica-bearing fluids of cyclically varying composition.
Evidence grade AScope: Describes the filling/precipitation mechanism for Deer Creek fire agate; not generalised as definitive for all localities.
Sources Journal article (Deer Creek fire agate)
Fire agate forms veins within its volcanic host rock; agates (banded chalcedony) commonly form by cyclic filling of cavities in volcanic rock with silica fluids.
Evidence grade AScope: Occurrence of fire agate/agate; not tied to a specific locality.
Sources Journal article (Deer Creek fire agate) · G&G Fall 2013
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
North America
- Southwestern United StatesFound in only a few places
Sources Gems & Gemology Winter 2015
- Mexico
Sources Gems & Gemology Winter 2015
- El Terrero mine, Calvillo Mountains, Aguascalientes, MexicoLocality of the studied sample
Sources Gems & Gemology Winter 2015
- Deer Creek, Arizona, United States
Sources Journal article (Deer Creek fire agate)
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
The fire effect of fire agate is linked to the colloform texture formed by poorly ordered chalcedony with mogánite, micro-quartz and opal-C; the multi-layered silica spheroidal forms could be centres of reflection and interference of white light.
Evidence grade AScope: A mechanism hypothesis for the fire effect; the source words it as 'seems to be responsible'/'could be', not a definitive cause.
Sources Journal article (Deer Creek fire agate)
Scattered pigments within the silica matrix give fire agate its red-brown body colour: minute iron oxides (magnetite, maghemite) together with titanium oxides (rutile, anatase).
Evidence grade AScope: Colour cause for Deer Creek fire agate; other localities with different colouring phases are not excluded.
Sources Journal article (Deer Creek fire agate)
How it is identified
The colour and inclusion appearance of 'fire-agate' cannot establish whether a stone is natural, synthetic or treated: quartz varieties that look alike may differ entirely in composition, growth history and treatment, and synthetic and natural quartz share essentially the same composition and physical properties, so the unaided eye cannot separate them. Laboratory identification rests on measurable properties and the division of labour between instruments — a polariscope with a conoscope lens can judge colour-zoning orientation from extinction and optic-axis readings, a refractometer gives refractive-index values, and EDXRF with infrared spectroscopy supplies chemical and structural fingerprints. Limitations: some methods depend on how the stone was cut and on comparison with reference material, and the final conclusion must be issued by an accredited gemological laboratory through testing rather than inferred from appearance.
Evidence grade AScope: Identification and separation points; testing must be performed by an accredited gemological laboratory, and no self-test thresholds are given.
Sources G&G Summer 2014 · CIBJO Gemstone Book 2022
Other research findings
Fire agate is a variety of agate (chalcedony, cryptocrystalline quartz) showing iridescent fire against a brown body colour; it is not an independent mineral species.
Evidence grade BScope: An identity/variety-boundary judgement; it does not confirm any sample's origin or treatment.
Sources Journal article (Deer Creek fire agate) · G&G Fall 2013
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- Fire agate is a chalcedony-variety agate, not an independent mineral species; the fire and colour causes rest mainly on a single Deer Creek study.
- No authoritative source on fire agate from other localities has been found; origin and treatment are not judged from the name.
- Not a grade or value judgement.
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 Agate
CIBJO Gemmological Laboratories Book 2024 §7.2.1.3 “Agate” · IMA Mineral List 2026-07 “Quartz”
Construction or treatment status
Natural identity; treatment status unknown
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 Agate's material identity has open questions that are not fully settled; this site lists it as "Fire Agate" pending further verification.
Evidence
- CIBJO · 7.2.1.3
What this means for you
Before buying, check the recommended listing name "Fire Agate" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- This entry's exact material identity is not fully settled.
- See “Disclosure and cautions” above
- Last reviewed
- 2026-09-26
Care and wear
No care facts are recorded for this entry itself. Its parent material has care records: see Agate.
VerifyNames, standards, technical facts, clauses and sources
Names
Trade and mineralogical namesFire Agate is a commercial/trade name. Recommended listing nameThe suggested listing name is Fire Agate. Names in four languagesIt is written in Simplified Chinese, Traditional Chinese, English (Fire Agate) and Japanese (pending verification). The formal name of Japan's GSJ is provisionally shown as the Japanese form marked pending verification, but the wording of Japan's GSJ for it is not yet verified by this site, and the entry's own Japanese name is shown. Chinese standard nameOn Chinese standard naming, the Chalcedony (Agate/Jasper) row of GB/T 16552—2017 Table A.2 gives the counterpart agate, and the name Fire Agate itself is not listed in the original. Institution usageOn authority wording, the FTC text on file has been checked and has no wording for Fire Agate; the wording of GIA, CIBJO and Gem-A is not yet verified by this site. Bodies without a recorded wording show the entry's own English name, which does not represent their position. Mineralogically, Fire Agate is a largely opaque agate showing iridescent colours against a brown body colour, a chalcedony and quartz material.
- GSJ (Japan) formal name
- ファイア・アゲート（待核） (not yet checked for this body — the entry's own Japanese name is shown)
- GB/T naming counterpart (this name is not in the standard)
- 玛瑙 (GB/T 16552—2017 Table A.2, row “Chalcedony(Agate/Jasper)”)
- Mineralogical name
- Fire agate: largely opaque agate (chalcedony, quartz) with iridescent colours against a brown body colour
Four-language names
- 简体中文
- 火玛瑙
- 繁體中文
- 火瑪瑙
- English
- Fire Agate
- 日本語
- ファイア・アゲート（待核）
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Quartz and chalcedony materials
- Identity tier
- Commercial / trade name
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
Among the registered material facts for Fire Agate, the composition (phase) is quartz. Chemical composition, fluorescence, UV-visible spectrum, infrared spectrum and magnification are given in the cited clauses for chalcedony (including agate and jasper, the whole class) and are not repeated for Fire Agate; see the material facts of the Chalcedony entry. Mohs hardness, density and refractive index are also taken for chalcedony (including agate and jasper, the whole class): Mohs hardness 5–7, density 2.5–2.77 g/cm³ and refractive index 1.535–1.539; this site notes that the refractive index clause has further sub-grades and the overall value is registered. Fire Agate is mostly opaque; the body colour of untreated Fire Agate is iridescence shown on a brown body colour. This site adds that in Chapter 7 of the CIBJO Gemmological Laboratories Book, the entries for agate, smoky quartz and morion likewise record the colour as brown or brownish, and notes that colour alone cannot be used to establish identity or natural origin.
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 chalcedony, including agate and jasper (the whole class), so they are not repeated on the Fire Agate page; see the material facts on the Chalcedony entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Fire Agate (how to read class-level values).
Definition
Fire Agate — composition (phase): quartz
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Durability
Fire Agate — Mohs hardness: 5–7
GB/T 16553—2017
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))
- Does this standard apply
- applies to this entry
- What this covers
- chalcedony, including agate and jasper (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.5 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Fire Agate — density: 2.5–2.77 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- chalcedony, including agate and jasper (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.5 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Fire Agate — refractive index: 1.535–1.539
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- chalcedony, including agate and jasper (the whole class)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.5 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Fire Agate — transparency: largely opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Fire Agate — body colour: iridescent colours against a brown body colour
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Agate, Smoky Quartz, Morion / very dark Smoky Quartz and other entries also name brown or a brownish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- 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): 1.537 / 2.63; Closest values: 1Amethyst 1.548 / 2.67, 2Charoite 1.554 / 2.66, 3Changhua Stone 1.56 / 2.6, 4Shoushan Stone 1.56 / 2.7, 5Balin Stone 1.56 / 2.55
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
On testing and market, the conclusion on synthetics is that no synthetic Fire Agate is available on the market. This conclusion is cited from the CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022).
How far testing can go
Fire Agate — synthetic counterpart on the market: No synthetic counterpart of this material is commercially available
CIBJO Gemstone Book 2022
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- 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.
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.
- eCFR (United States). 16 CFR Part 23 — Guides for the Jewelry, Precious Metals, and Pewter Industries.
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 Quartz on this site: 74 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Fire Agate) is marked.
- Quartz
Sub-entries (57)
- Agate
Sub-entries (1)
- Fire Agate
- Amethyst
- Ametrine
- Aventurine Quartz
- Aventurine Quartz / Green Aventurine
- Banded Agate
- Black Agate
- Bloodstone / Heliotrope
- Blue Lace Agate
- Carnelian
- Chalcedony
Sub-entries (2)
- Chrysoprase
- Citrine
- Clear Quartz / Rock Crystal
- Coated Quartz
- Colourless to White Quartz (brand name: Azeztulite)
- Crazy Lace Agate
- Dendritic Agate
- Dyed Agate (Treated: dyed)
- Elestial Quartz / Skeletal Quartz
- Eye Agate
- Flower Agate / Cherry Blossom Agate
- Green Quartz
- High-clarity quartz with golden needle-like inclusions
- Included Quartz
- Jasper
Sub-entries (1)
- Madeira Citrine
- Malachite Agate
- Morion / very dark Smoky Quartz
- Moss Agate
- Moss Chalcedony
- Multi-inclusion Quartz
- Onyx (banded chalcedony)
- Phantom Quartz
- Prase
- Prasiolite / Green Quartz
- Quartz Cat’s-eye
- Quartz claimed to be from the Himalayas
- Quartz Crystal
- Quartz with dark needle-like inclusions
- Quartz with fine fibrous inclusions
- Quartz with flower-like inclusions
- Quartz with golden needle-like inclusions
- Quartz with green needle-like inclusions
- Quartzite Jade
- Quartzose Jade
- Red Agate
- Rock Crystal
- Rose Quartz
- Rutilated Quartz
- Sard
- Sardonyx
- Silicified Asbestos
Sub-entries (2)
- Hawk’s Eye
- Tiger’s Eye
Sub-entries (1)
- Smoky Quartz
- Smoky Quartz (brown variety)
- Strawberry Quartz
- Yellow-green Quartz
- Agate
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Quartz and chalcedony materials | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Fire Agate 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. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.