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Natural inorganic gem materials · Trade name: colour / appearance variety · Natural identity; treatment status unknown
Flux-Healed Ruby
Also known asFlux-assisted heated ruby · Flux-healed
Ruby whose fractures have been healed by heat treatment with a flux; residual flux is not a natural inclusion and must be disclosed. 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 Flux-Healed Ruby forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify Flux-Healed RubyIdentification points from the research literature
- Treatments and enhancements of Flux-Healed Ruby1 registered treatments: status, stability, how common they are and identification leads
- Flux-Healed Ruby 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 Flux-Healed RubyThe 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
A ruby described as flux-healed is natural corundum whose fractures have been closed by a heat treatment carried out with the aid of a flux. The process works by dissolving material at elevated temperature and re-precipitating it as the stone cools. CIBJO classifies this among the flux assisted heat treatments applied to corundum, and notes that once the fissures close, silicate glass is caught inside the original cracks and is commonly called 'residues'. Under the trade naming system the treatment is written as 'Heated in flux', with the code FAH (Flux assisted healing). The stone is therefore a treated gem product rather than something nature made: only the corundum host is natural, whereas the healed fractures and the trapped glass both come from the man-made heating step.
Scope: Used to describe corundum (ruby) whose fractures have been healed at high temperature with the aid of a flux and that contains glassy residues; emphasises that it is a treated gem product, not naturally formed; the healing and glassy residues result from artificial heat treatment.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
Where it forms
Non-natural setting: flux assisted healing is carried out artificially in a high-temperature furnace/kiln and does not occur in a geologic environment.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
The host ruby's natural origin is basalt-hosted or metamorphic (marble-hosted) corundum deposits (e.g. Mozambique, Myanmar, Thailand and others).
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
How it forms, step by step
Fractured natural corundum (ruby) is subjected to a high-temperature heat treatment aided by a flux.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
The fissures undergo dissolution at high temperature and are re-deposited upon cooling, so the fissures heal (healing of fissures).
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
Closing of the fissures traps silicate glass inside the pre-existing cracks, and the resulting glass is commonly termed 'residues'.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
Link to appearance
After healing, fracture visibility is reduced and the clarity appearance improves; glass residues can remain within the healed fissures and are one basis for a laboratory to identify flux healing.
Sources CIBJO Gemstone Book 2022
Timescale
The sources give no absolute age for the host and no duration for the healing treatment; it takes place in a high-temperature furnace during processing.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2015
Related base materials
- Ruby (red gem variety of corundum): part-of | The treated host is natural ruby (corundum)
- Flux and glass residues (silica glass trapped in healed fissures): healed-into | Flux assists high-temperature healing of fissures; during healing, silicate glass is trapped as residues
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Montepuez, Cabo Delgado, MozambiquePre-treatment source; seen at GIA Bangkok from 2009
Sources GIA Laboratory Bangkok report
Asia
- Mong Hsu, Shan State, MyanmarPre-treatment source; flux-assisted healing used on Mong Hsu material since the early 1990s
Sources GIA Laboratory Bangkok report
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 the origin determination guide and the overview of recorded localities.
How it is identified
Flux-healed ruby has its fractures healed by a flux treatment, and the healed areas can resemble natural healed fractures or other fillings, making visual separation difficult. Recognition is done in a laboratory, typically using microscopic and immersion examination, Raman spectroscopy, and energy-dispersive or mass spectrometric compositional analysis to confirm residual flux components at the healed areas. Treatment determination must be issued by an accredited laboratory, and this entry provides no self-test criterion, threshold, or separation procedure.
Evidence grade AScope: Safety boundary: appearance is insufficient to decide flux-healing treatment; determination requires testing by an accredited laboratory, and this entry gives no self-test criteria or separation procedure.
Origin determination concerns natural material, whereas flux-healed ruby is a gem product healed by artificial heat treatment, to which natural origin determination does not apply. For such material the treated or synthetic status must itself first be established by an accredited laboratory using instrumental testing; until then an origin discussion is meaningless. Origin cannot be inferred from appearance or name; and even where some natural material is involved, any origin claim must be issued by an accredited laboratory for a specific specimen. No self-test criteria are given here.
Evidence grade AScope: Origin cannot be inferred from appearance or name; natural origin determination does not apply to this material and its treated/synthetic status must first be established by a laboratory; any conclusion must be issued by an accredited laboratory for a specific specimen; no self-test criteria are given here.
Other research findings
Flux assisted healing is one of the flux-aided heat treatments applied to corundum: it closes fissures by dissolving material at elevated temperature and letting it deposit again as the stone cools.
Evidence grade AScope: CIBJO's terminology definition of flux assisted healing (5.31); it gives no specific process parameters.
Sources CIBJO Gemstone Book 2022
Silica glass is trapped inside the original fissures once they close, and such glass is commonly termed 'residues'.
Evidence grade AScope: CIBJO's description of the residues; the residues are products of the artificial heat treatment.
Sources CIBJO Gemstone Book 2022
The CIBJO trade code FAH denotes flux assisted healing, described as 'Heated in flux', meaning corundum showing indications of heat treatment with a degree of healing along previous fractures and containing glass residues from the heating process.
Evidence grade AScope: CIBJO's trade-code table and the clause 4.2.5.2 chart; it applies to flux-healed corundum.
Sources CIBJO Gemstone Book 2022
Ruby's older-style heating can proceed either with borax-type additives or without them, and it targets stones that are less heavily fractured and show a milky or silk-like look; this suggests that adding flux (borax-type additives) is tied to how fractured the material is.
Evidence grade AScope: Concerns processing practice for Mozambique (Montepuez) ruby; practice elsewhere may differ.
A flux-healed ruby is a treated gem product, not a natural formation (not an independent material); its healing and glass residues come from the artificial heat treatment.
Evidence grade AScope: Based on CIBJO's definitions of treatment and flux assisted healing; whether a given stone is flux-healed must be confirmed by a laboratory.
Sources CIBJO Gemstone Book 2022
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The flux-healing terminology comes from the CIBJO standard; the cited GIA sources only give indirect evidence via borax-like additives and do not directly describe the flux-healing process.
- Whether a given stone is flux-healed must be confirmed by a gem laboratory.
- The sources give no duration for the healing treatment and no absolute age for the host.
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
- Flux-healed Ruby
16 CFR Part 23 §23.24
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Heated / Heat-treated (via parent material), Dyed (via parent material), Filled / Fracture-filled (via parent material), Diffusion-treated (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
"Flux-Healed Ruby" is a market name rather than a mineral species name; before using it, verify: Composition or process must be stated.
Evidence
What this means for you
Before buying, check the recommended listing name "Flux-healed Ruby" 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
- 2026-09-01
Trade-name ruling
- Composition or process must be stated.
- Suggested listing name
- Flux-healed Ruby
Treatments and identification leads
Values not givenThe treatment registered for Flux-Healed Ruby is heating, with the status treated; stability and prevalence are both marked “—”, meaning the cited source gives no value, not “none”. Identification cluesThe identification leads for this treatment are: under magnification, the surface shows traces of partial melting, solid inclusions are surrounded by disc-like or ring-shaped stress fractures, the rims of negative crystals are corroded or rounded, and silk and needle inclusions are broken into segmented threads or tiny dots. The source of these leads is GB/T 16553—2017.
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| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| heatingStatus: treated | — | — | Optimization | — | See identification leads |
| Dyeing | — | — | Treatment | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Diffusion | — | — | Treatment | — | — |
Where each treatment acts (schematics): Heated / Heat-treated
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16553—2017; GB/T 16552—2017 Table B.1 (row for Ruby)
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
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Flux-Healed Ruby, the name register records "Flux-assisted heated ruby" and "Flux-healed", for which no restriction on use as a name is recorded.
Standard and listing namesThe national-standard name corresponding to Flux-Healed Ruby is ruby (GB/T 16552—2017); this name is not listed in the original text. The suggested listing name is Flux-Healed Ruby. Names in four languagesThe four-language names cover Simplified Chinese, Traditional Chinese, English (Flux-Healed Ruby) and Japanese. Institution usageOn authority wording, the FTC and CIBJO texts have no wording for this name (checked), and GIA and Gem-A are unchecked; bodies without a record show the entry's own English name, which does not represent their position. Japanese namesThe GSJ (Japan) wording for the entry's own Japanese name is not yet verified by this site. Trade and mineralogical namesThe mineralogical description is ruby whose fractures have been healed by flux-assisted heat treatment; trade names and synonyms are Flux-healed and Flux-assisted heated ruby, both registered as English market names that may be matched automatically to Flux-Healed Ruby. In the classification, the identity tier is trade name (colour/appearance variety).
Name register
Every name recorded for this entry, with how it is classified, whether it may be matched to this entry automatically, whether it may be used as a product name, and the clause it rests on.
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| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (2) | ||||
| Flux-assisted heated rubyEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| Flux-healedEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- フラックスヒールド・ルビー (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)
- 红宝石 (GB/T 16552—2017 §5.4.2.1 a))
- Mineralogical name
- Ruby with fractures healed by flux-assisted heat treatment
- Trade names and synonyms
- Flux-healed (market name) · Flux-assisted heated ruby (market name)
Four-language names
- 简体中文
- 助熔剂愈合红宝石
- 繁體中文
- 助熔劑癒合紅寶石
- English
- Flux-Healed Ruby
- 日本語
- フラックスヒールド・ルビー
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Oxide minerals
- Identity tier
- Trade name: colour / appearance variety
- Mineral chemical class
- Oxides / hydroxides
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
This site classifies the enhancements and treatments of Flux-Healed Ruby by applying the Ruby row of GB/T 16552—2017 Annex B, Table B.1: heat treatment is listed as an enhancement, dyeing as a treatment, diffusion as a treatment, and filling by grade, with each grade defined on the Gem treatments page. The full row, with the effect column, is on the Ruby entry, and the notes to Table B.1 are also on the Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Under the “Ruby” row of Table B.1: Heating Optimization; Dyeing Treatment; Filling Graded — see §5.4.1, Table 1; Diffusion Treatment. The full row, with the effect column, is on the Ruby 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.
What it is and how it's identified
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”.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Flux-Healed Ruby (how to read class-level values).
Care
The item-by-item care advice that the GIA Care and Cleaning Guide gives for the whole class, and so for Flux-Healed Ruby, is set out in full under care on the Ruby entry.
How far testing can go
The CIBJO laboratory protocol covers Flux-Healed Ruby under “Ruby” (§6.1.68): see identification on the Ruby entry; the required tests are listed on the CIBJO laboratory protocol table for Ruby.
Flux-Healed Ruby that has undergone heating can be identified by the following features: Under magnification the surface of the stone shows traces of local melting, platy or ring-like stress fissures appear around solid inclusions, negative crystals look corroded or rounded at the rim, and silk and needle inclusions break up into short lengths of silk or fine dots.
GB/T 16553—2017
- Treatment state
- treated
- Does this standard apply
- can be followed as a reference only
- What this covers
- ruby as a whole (not one origin)
- Treatment
- heating
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.2 (heating) (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
How lab reports word it
Report wording for Flux-Healed Ruby is set out under report wording on the Corundum entry.
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.
- GIA – Gemological Institute of America (United States). Gem Encyclopedia.
- Gem-A – The Gemmological Association of Great Britain (United Kingdom).
- Federal Trade Commission (United States). In the Loupe: Advertising Diamond, Gemstones and Pearls.
- eCFR (United States). 16 CFR § 23.24 — Disclosure of treatments to gemstones. In: 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.
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| Page | Content | Status |
|---|---|---|
| Browsing family | Oxide minerals | Live |
| Treatments recorded for this material | Heated / Heat-treated (via parent material), Dyed (via parent material), Filled / Fracture-filled (via parent material), Diffusion-treated (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Flux-Healed Ruby 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.