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Natural inorganic gem materials · Trade name: colour / appearance variety · Natural identity; treatment status unknown
Irradiated Blue Topaz
Also known asBlue Topaz (conditional name) · London blue · Sky blue topaz · Swiss blue
Colourless topaz turned blue by irradiation (often followed by heating); Swiss, London and Sky blue are trade colour grades, and the treatment must be disclosed. Also known as Swiss blue, London blue. 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 Irradiated Blue Topaz forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify Irradiated Blue TopazIdentification points from the research literature; how far lab testing can go
- Treatments and enhancements of Irradiated Blue Topaz1 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing Irradiated Blue TopazCleaning, heat, chemicals and light, as the cited sources give them
- Irradiated Blue Topaz 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 Irradiated Blue TopazThe 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
Irradiated blue topaz is a treated gem product: colourless (or pale) natural topaz is turned blue by artificial irradiation, often followed by heating; it is not formed in nature. CIBJO defines irradiation as subjecting gemstones, diamonds, pearls, cultured pearls as well as artificial products to radiation of any kind that humans control wholly or in part, normally in order to change how they look, and defines heating as changing a stone through a thermal process — in a furnace, kiln or other heating device — so as to alter its colour, its clarity, or both. The blue colour is therefore the result of artificial treatment. The cited authoritative sources give no specific radiation type, dose or heat-treatment parameters for topaz, so this entry states only the defined treatment category, its effects and its naming boundary and does not invent parameters.
Scope: Applies to treated gem products in which colourless / pale natural topaz is turned blue by artificial irradiation (often followed by heating); not applicable to untreated topaz, and not an identification conclusion for any specific sample.
Sources CIBJO Gemstone Book 2022
Where it forms
No natural formation environment applies: this is the result of artificial irradiation (often then heating); the treatment environment is a controlled radiation source and a heating apparatus (furnace, kiln), and the sources give no specific temperature or dose.
Sources CIBJO Gemstone Book 2022
Its parent is natural topaz; the natural occurrence environment of topaz is outside this record, which describes only the irradiation/heating treatment.
Sources CIBJO Gemstone Book 2022
How it forms, step by step
Select colourless or pale natural topaz, rough or fashioned.
Sources CIBJO Gemstone Book 2022
Apply radiation controlled wholly or partially by man to change its colour.
Sources CIBJO Gemstone Book 2022
Often then heat it, to stabilise or adjust the resulting blue colour (as the record itself describes).
Sources CIBJO Gemstone Book 2022
Per CIBJO naming rules, the finished stone must be named as a treated product and the irradiation treatment disclosed.
Sources CIBJO Gemstone Book 2022
Link to appearance
The blue appearance is produced by artificially changing the colour through irradiation (and the heating that often follows), yielding blues of different intensity; the colour is a treatment result, not the original colour of untreated natural topaz.
Sources CIBJO Gemstone Book 2022
Timescale
The sources state no process duration for the topaz irradiation/heat treatment and no historical date for its use.
Sources CIBJO Gemstone Book 2022
Related base materials
- Topaz: Natural colourless parent material whose colour has been changed by irradiation (often followed by heating)
How it is identified
Irradiated blue topaz looks virtually the same as blue topaz coloured by other means, and the eye cannot tell whether the colour came from irradiation, a treatment that usually leaves no visible trace. Judging the colour cause relies on laboratory testing such as spectroscopy and compositional analysis; treatment status must be determined by an accredited laboratory, and this entry gives no self-test criteria or threshold.
Evidence grade AScope: Appearance is insufficient to settle the colour cause; determination requires testing by an accredited laboratory, and this entry gives no self-identification method or threshold.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2019
Other research findings
CIBJO defines irradiation as subjecting gemstones, diamonds, pearls, cultured pearls as well as artificial products to radiation of any kind that is controlled, wholly or partly, by humans, normally to change how they look. The blue of irradiated blue topaz arises from this artificial treatment.
Evidence grade AScope: Applies to CIBJO's definition of irradiation; it does not cover specific radiation types or doses.
Sources CIBJO Gemstone Book 2022
CIBJO defines heating as changing a stone through a thermal process — in a furnace, kiln or other heating device — so as to alter its colour, its clarity, or both. Blue topaz that has been irradiated is frequently heated afterwards, a second treatment employed alongside irradiation.
Evidence grade AScope: Applies to CIBJO's definition of heating; the sources give no specific temperature or time.
Sources CIBJO Gemstone Book 2022
Irradiation is a treatment type CIBJO lists as requiring disclosure (coded as 'artificial irradiation'); irradiated blue topaz must therefore be named and disclosed as treated, not presented as untreated natural material.
Evidence grade AScope: Applies to CIBJO's treatment-type/code table and disclosure naming rules; it makes no claim about any specific specimen.
Sources CIBJO Gemstone Book 2022
The US Nuclear Regulatory Commission (NRC) states that irradiation in a nuclear reactor or an accelerator can make gemstones radioactive, while gamma irradiation such as in a cobalt irradiator does not. The NRC regulates the initial distribution of such stones: the first transfer must be made under an NRC distribution licence, the stones are set aside, typically for a couple of months, so that the radioactivity can decay, and the licensee must survey them to verify that they meet NRC requirements for exempt distribution before they go on the market. The NRC lists irradiated gemstones among products distributed to exempt persons under Subpart A of 10 CFR Part 32. Under 10 CFR 30.14(d), introducing byproduct material into a product intended for exempt persons requires a licence issued under 10 CFR 32.11, and 10 CFR 32.11(c) requires reasonable assurance that concentrations at the time of transfer will not exceed those listed in 10 CFR 30.70.
Evidence grade AScope: Summarises NRC text and US federal regulations current in October 2026 only; it applies to the United States and not to other jurisdictions. The cited rules do not name specific nuclides or numerical limits for gemstones. Not legal advice. Not medical advice.
Sources NRC Backgrounder on Irradiated Gemstones · NRC Product Manufacturing and Distribution · 10 CFR 30.14 (US) +2
- Backgrounder on Irradiated Gemstones (U.S. Nuclear Regulatory Commission, March 2024)
- Product Manufacturing and Distribution of Radioactive Material (U.S. Nuclear Regulatory Commission)
- 10 CFR 30.14 Exempt concentrations (eCFR, up to date as of 2026-10-06)
- 10 CFR 32.11 Introduction of byproduct material in exempt concentrations into products or materials, and transfer of ownership or possession: Requirements for license (eCFR, up to date as of 2026-10-06)
- 10 CFR 30.70 Schedule A—Exempt concentrations (eCFR, up to date as of 2026-10-06)
According to the NRC, once the radioactivity has decayed and the stones have been distributed, irradiated gemstones are exempt from NRC regulations, and no licence is needed to own or sell them. The NRC says it has no reason to believe that wearing irradiated gemstones can be harmful; it estimated that a six-carat blue topaz at the highest radioactivity allowed under its regulations could give a dose of 0.03 millirem in the first year.
Evidence grade AScope: Summarises the NRC backgrounder dated March 2024 only; US scope. It is not a measurement of any particular stone. Not medical advice. Not legal advice.
Sources NRC Backgrounder on Irradiated Gemstones
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The authoritative sources give no specific radiation type, dose or heat-treatment parameters for topaz.
- The sources give no date of first use or process duration for the irradiation/heating treatment.
- The sources do not discuss the colour stability, fading or care of irradiated blue topaz, so this record makes no such claim.
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
- Irradiated Blue Topaz (state the specific colour grade)
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), Irradiated, Diffusion-treated (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
Under the naming rules of the Chinese standard (GB/T 16552—2017 §5.4.2.2 a)), Irradiated Blue Topaz takes a composed Chinese name that differs from its common trade name; use "Irradiated Blue Topaz (state the specific colour grade)" for listings.
Evidence
What this means for you
Before buying, check the recommended listing name "Irradiated Blue Topaz (state the specific colour grade)" 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
- Not a mineral: man-made or non-mineral material.
- Suggested listing name
- Irradiated Blue Topaz (state the specific colour grade)
Care and wear
The item-by-item care advice that the GIA Care and Cleaning Guide gives for the whole class, and so for Irradiated Blue Topaz, is set out in full under care on the Topaz entry.
Care
Irradiated Blue Topaz — care (special care): irradiated from brown (often then heated) to blue: normal care; if neutron-irradiated, follow the irradiation-code safety rules.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- heating, irradiation
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XV, Gemstone Information Chart, Topaz Blue R, 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
Registered treatmentsThe treatment recorded for Irradiated Blue Topaz is irradiation. Values not givenIts status is irradiated or dyed; stability and prevalence are both marked with a dash, which, as in the source wording, means the cited source gives no value, not none. Identification cluesAs identification leads: colourless topaz can turn deep blue or brownish green after irradiation and is often heated afterwards to obtain blue; yellow, orange and brownish green topaz may deepen in colour or have unwanted tints removed by irradiation; and irradiation is difficult to detect. The source is GB/T 16553—2017.
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| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| irradiationStatus: irradiated or dyed | — | — | Treatment | irradiation | See identification leads |
| Heating | — | — | Optimization | — | — |
| Diffusion | — | — | Treatment | — | — |
| Coating | — | — | Treatment | — | — |
Where each treatment acts (schematics): Irradiated
“—” 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 Topaz); 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
Besides Irradiated Blue Topaz, the name register records "Blue Topaz", "London blue", "Sky blue topaz" and "Swiss blue", for which no restriction on use as a name is recorded (JJA/AGL Gemstone Nomenclature 2025 p.14); one further name in a non-Latin script is listed in the name register below (1 with no restriction recorded on use as a name).
Names in four languagesThe four-language names of Irradiated Blue Topaz are given in Simplified Chinese, Traditional Chinese, English (Irradiated Blue Topaz) and Japanese (meaning irradiated blue topaz). Chinese standard nameThe name formed under the GB/T 16552—2017 naming rules is irradiated topaz, with the basic name topaz; the original does not list irradiated topaz separately. Trade and mineralogical namesTrade names/synonyms include Swiss blue, London blue and Sky blue topaz. Recommended listing nameThe suggested listing name is irradiated blue topaz (stating the specific colour grade). Institution usageOn authority wording, among GIA, FTC, CIBJO and Gem-A, the FTC and CIBJO texts on file have no wording for Irradiated Blue Topaz (checked), and GIA and Gem-A are unchecked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe entry's own Japanese name means irradiated blue topaz, and Japan's GSJ wording for it is not yet verified by this site. The Japanese JJA/AGL Gemstone Nomenclature 2025 registers Blue Topaz, to be matched only once the condition is confirmed. Candidate search termsIts Japanese katakana form is a transliteration and serves only as a search candidate.
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 (5) | ||||
| Blue TopazEnglish | market name | matched only once the condition is confirmed | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.14 |
| London blueEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| Sky blue topazEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| Swiss blueEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| ブルー・トパーズJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.14 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 照射ブルートパーズ (not yet checked for this body — the entry's own Japanese name is shown)
- Name built by the GB/T naming rules (not listed as such)
- 辐照托帕石 (GB/T 16552—2017 §5.4.2.2 a); basic name 托帕石)
- Mineralogical name
- Colourless topaz turned blue by irradiation (often followed by heat)
- Trade names and synonyms
- Swiss blue (market name) · London blue (market name) · Sky blue topaz (market name) · Blue Topaz (market name; conditional name)
Four-language names
- 简体中文
- 辐照蓝色托帕石
- 繁體中文
- 輻照藍色託帕石
- English
- Irradiated Blue Topaz
- 日本語
- 照射ブルートパーズ
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Other silicate minerals
- Identity tier
- Trade name: colour / appearance variety
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
GB/T Table B.1For the optimizations and treatments listed in the standard, this site applies the “Topaz” row of GB/T 16552—2017 Annex B, Table B.1 to Irradiated Blue Topaz: heating is listed as optimization; irradiation, diffusion and coating are all listed as treatment, and the full row, with the effect column, is on the Topaz entry. The notes to Table B.1 and the definitions of the optimization and treatment categories are on this site's Gem treatments page. JJA/AGL designationsThe 2025 revision of the Japanese JJA/AGL Definitions and Nomenclature of Gemstones and Ornamental Materials, in its list of main gemstone designations, lists Blue Topaz with species topaz and colour blue, and the treatment listed is irradiation (irradiation treatment); this site notes that Irradiated Blue Topaz is a related entry and the original does not name Irradiated Blue Topaz specifically. How to read the JJA/AGL table is explained on the Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Under the “Topaz” row of Table B.1: Heating Optimization; Irradiation Treatment; Diffusion Treatment; Coating Treatment. The full row, with the effect column, is on the Topaz 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
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| Gem name | Species | Colour | Listed in the table | Notes |
|---|---|---|---|---|
| Blue Topaz | Topaz | blue | irradiation (Irradiated) | listed under “Blue Topaz” in the table; this page is related (the source does not name it) |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.14
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
The optical item listed among the registered material facts for Irradiated Blue Topaz is pleochroism, shown as blue of different tones; the source is GB/T 16553—2017 Gems — Testing, and the registered treatment state is 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”.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Irradiated Blue Topaz (how to read class-level values).
Optical
Irradiated Blue Topaz — pleochroism: blue of different tones
GB/T 16553—2017
- 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): §5.1.13 Pleochroism · Blue (locator checked 2026-09-28)
- 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.
Testing and market
For the identification of Irradiated Blue Topaz, the CIBJO laboratory protocol places Irradiated Blue Topaz under the "Topaz" entry; for identification see the Topaz entry, and the list of required methods is on the laboratory testing page. For irradiated Irradiated Blue Topaz, the identification leads are: colourless topaz can turn deep blue or brownish green after irradiation and is often further heated to obtain blue; yellow, orange and brownish-green topaz can be deepened in colour and have unwanted tints removed by irradiation; irradiation is difficult to detect. The leads are registered for topaz as a whole mineral species with treatment status irradiated or dyed, from GB/T 16553—2017, which can only be used as a reference for Irradiated Blue Topaz and does not govern it directly.
The CIBJO laboratory protocol covers Irradiated Blue Topaz under “Topaz” (§6.1.85): see identification on the Topaz entry; the required tests are listed on the CIBJO laboratory protocol table for Topaz.
How far testing can go
Irradiated Blue Topaz that has undergone irradiation can be identified by the following features: Irradiation turns colourless topaz deep blue or brown-green, and it is commonly heated afterwards to give blue; yellow, orange and brown-green topaz can be irradiated to deepen the colour or to remove an unwanted secondary colour. Hard to detect.
GB/T 16553—2017
- Treatment state
- irradiated or dyed
- Does this standard apply
- can be followed as a reference only
- What this covers
- topaz (the whole mineral species)
- Treatment
- irradiation
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.13 (irradiation) (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.
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 | Other silicate minerals | Live |
| Treatments recorded for this material | Heated / Heat-treated (via parent material), Irradiated, Diffusion-treated (via parent material), Coated (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Irradiated Blue Topaz 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.