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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral group / supergroup · Natural identity; treatment status unknown
Taaffeite Group
Also known asFerrotaaffeite-2N'2S · Ferrotaaffeite-6N'3S · Magnesiotaaffeite-2N'2S · Magnesiotaaffeite-6N'3S · Musgravite (conditional name)
The IMA list splits the former taaffeite into the Magnesiotaaffeite and Ferrotaaffeite series of mineral species; identifying the species requires LA-ICP-MS testing. Also known as Musgravite. 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 Taaffeite Group 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 Taaffeite GroupHow far lab testing can go
- Caring for and wearing Taaffeite GroupCleaning, heat, chemicals and light, as the cited sources give them
- Taaffeite Group 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 Taaffeite GroupThe listing name to use; what must be disclosed before sale
- Standard clauses that define Taaffeite GroupWhich 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
"Taaffeite group" is a mineralogical group/higher-level name corresponding to several IMA species distinguished by Mg/Fe and stacking sequence: Magnesiotaaffeite-2N'2S, Magnesiotaaffeite-6N'3S, Ferrotaaffeite-2N'2S and Ferrotaaffeite-6N'3S. These are beryllium-, magnesium- and aluminium-bearing oxides, and species assignment requires advanced laboratory testing. The CIBJO standard, by contrast, lists "Taaffeite" as a single mineral species name and marks it no treatment (always). GIA reported a chromium-bearing purplish red taaffeite from Sri Lanka hosting a minute black crystal (most likely thorianite or uraninite); alpha emissions from such radioactive inclusions damage the host, producing a two-tiered concentric halo and locally changing the host's colour, transparency and refractive index. Note: the cited sources do not describe the specific formation process or absolute age of the taaffeite group.
Scope: Applies to explaining the naming boundary of 'taaffeite group' as a group / higher-level name, and the origin of radiation haloes in Sri Lankan samples recorded by GIA; does not include the specific mineral-forming process of the taaffeite group (no source on it has been found yet; see limitations).
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
Where it forms
Gem-quality occurrence of chromium-bearing taaffeite (e.g. Sri Lanka).
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
Micro-environment of radioactive thorianite/uraninite inclusions within the host taaffeite.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
How it forms, step by step
Taaffeite crystallizes as a beryllium-magnesium-aluminium oxide in specific geological settings and may contain minor chromium.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
During growth, minute black crystals (most likely thorianite or uraninite) are trapped as inclusions.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
The radioactive inclusions emit alpha particles that damage the host crystal, forming a two-tiered concentric halo.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
Link to appearance
The taaffeite described by GIA is chromium-bearing and purplish red; alpha radiation from its radioactive inclusions produces a two-tiered concentric halo with local changes in refractive index and transparency.
Sources G&G Spring 2016
Timescale
The sources give no absolute geological timescale for the formation of the taaffeite-group minerals.
Sources G&G Spring 2016
Related base materials
- Magnesiotaaffeite-2N'2S: One of the IMA mineral species of the taaffeite group
- Magnesiotaaffeite-6N'3S: One of the IMA mineral species of the taaffeite group
- Ferrotaaffeite-2N'2S: One of the IMA mineral species of the taaffeite group
- Ferrotaaffeite-6N'3S: One of the IMA mineral species of the taaffeite group
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Tunduru, TanzaniaSpecimen locality in Mindat
Sources Mindat: Magnesiotaaffeite-2N’2S
Asia
- Sri LankaBased on faceted stones in GIA's collection and G&G records
Sources GIA Gübelin Gem Project · G&G Spring 2016
- Mogok area, MyanmarGIA collection records Myanmar; Mindat lists Chaung-gyi, Mogok
Sources GIA Gübelin Gem Project · Mindat: Magnesiotaaffeite-2N’2S
- Niriella gem gravels, Ratnapura, Sri LankaType locality of magnesiotaaffeite-2N'2S
Sources Mindat: Magnesiotaaffeite-2N’2S
Oceania
- Musgrave Ranges, South Australia, AustraliaType locality of magnesiotaaffeite-6N'3S (musgravite); not a commercial gem source
Sources Handbook of Mineralogy
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 Sri Lankan taaffeite reported by GIA is a chromium-bearing purplish red gem material (the sample is from Sri Lanka).
Evidence grade AScope: For that sample; colour may differ in other localities or samples.
Sources G&G Spring 2016
A radiation-induced two-tiered halo can form in taaffeite, surrounding a minute black crystal.
Evidence grade AScope: A localized inclusion phenomenon, not the whole gem.
Sources G&G Spring 2016
Other research findings
The "taaffeite group" corresponds to several IMA species distinguished by Mg/Fe and stacking sequence (Magnesiotaaffeite-2N'2S, Magnesiotaaffeite-6N'3S, Ferrotaaffeite-2N'2S, Ferrotaaffeite-6N'3S); the CIBJO standard lists "Taaffeite" as a single mineral species name (no treatment, always). The name is therefore a group/higher-level name, not a single species.
Evidence grade AScope: Naming and classification; the species list follows IMA nomenclature and species assignment requires laboratory testing.
Sources CIBJO Gemstone Book 2022 · G&G Spring 2016
Because one name covers several species, this record does not attribute any single species' genesis or properties to the whole group; species assignment requires advanced laboratory testing.
Evidence grade BScope: A self-limitation of the record's scope.
Sources CIBJO Gemstone Book 2022
Powerful alpha emission from radioactive inclusions in a mineral can bring about stress fractures within the host crystal.
Evidence grade AScope: Describes a radiation-damage mechanism; not all taaffeite contains such inclusions.
Sources G&G Spring 2016
Limits of this research
- Research status: Only partial material-specific findings found; gaps are stated as gaps
- The cited sources do not describe the specific formation process of the taaffeite group (a formation evidence gap); this entry gives only occurrence and the inclusion-related radiation halo.
- The "taaffeite group" covers several species; the cited sources provide no quantitative data distinguishing their compositions (by Mg/Fe and stacking sequence).
- The black inclusion in the cited Sri Lankan sample could not be non-destructively identified due to its minute size; the source only suggests thorianite or uraninite.
- No absolute age for taaffeite-group formation is given by the sources.
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
- Taaffeite group (state the specific species)
IMA Mineral List 2026-07 “Magnesiotaaffeite-2N'2S”, “Magnesiotaaffeite-6N'3S”, “Ferrotaaffeite-2N'2S”, “Ferrotaaffeite-6N'3S”
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
"Taaffeite Group" is a market name rather than a mineral species name; before using it, verify: Industry-wide term that does not denote a single species.
What this means for you
Before buying, check the recommended listing name "Taaffeite group (state the specific species)" 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
- Industry-wide term that does not denote a single species.
- Suggested listing name
- Taaffeite group (state the specific species)
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.
Care
Taaffeite Group — care (cleaning): no ultrasonic cleaning
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code j
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Taaffeite, p.78; §6.2 j (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Common care questions and matching entries
Each question links to the matching entries on this page; whether they answer it fully, go by the entry wording.
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| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | no ultrasonic cleaning |
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Taaffeite Group, the name register records "Ferrotaaffeite-2N'2S", "Ferrotaaffeite-6N'3S", "Magnesiotaaffeite-2N'2S", "Magnesiotaaffeite-6N'3S" and "Musgravite", for which no restriction on use as a name is recorded (IMA Mineral List 2026-07 Ferrotaaffeite-2N'2S; IMA Mineral List 2026-07 Ferrotaaffeite-6N'3S; IMA Mineral List 2026-07 Magnesiotaaffeite-2N'2S; IMA Mineral List 2026-07 Magnesiotaaffeite-6N'3S; CIBJO Gemmological Laboratories Book 2024 §7.2.1.153 “Musgravite”).
Standard and listing namesThe GB/T naming counterpart for Taaffeite Group is “Taaffeite”, registered in GB/T 16552—2017 Table A.1; the GB/T 16552—2017 text does not list the Taaffeite Group. The suggested listing name is Taaffeite Group (stating the specific species). Names in four languagesThe four-language names are given in Simplified Chinese, Traditional Chinese, English (Taaffeite Group) and Japanese (a transliteration); the Japanese name is the entry's own, and the Japanese GSJ wording is not yet verified by this site. Institution usageAmong authority wordings, of GIA, FTC, CIBJO and Gem-A, the FTC and CIBJO source texts have no wording for this name (checked), and the wordings of GIA and Gem-A have not been checked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Trade and mineralogical namesThe mineralogical name is Taaffeite-group minerals, and the specific species must be determined by advanced testing. The IMA Mineral List 2026-07 lists Magnesiotaaffeite-2N'2S, Magnesiotaaffeite-6N'3S, Ferrotaaffeite-2N'2S and Ferrotaaffeite-6N'3S, all current species names after the IMA-CNMNC renaming of 2001. Candidate search termsMusgravite is a synonym registered in the CIBJO Gemmological Laboratories Book 2024 and is only a candidate search term.
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) | ||||
| Ferrotaaffeite-2N'2SEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | IMA Mineral List 2026-07 Ferrotaaffeite-2N'2S; Note: Current species name after the IMA-CNMNC 2001 renaming; the 2026-07 IMA list records it as Ferrotaaffeite-2N'2S. |
| Ferrotaaffeite-6N'3SEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | IMA Mineral List 2026-07 Ferrotaaffeite-6N'3S; Note: Current species name after the IMA-CNMNC 2001 renaming; the 2026-07 IMA list records it as Ferrotaaffeite-6N'3S. |
| Magnesiotaaffeite-2N'2SEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | IMA Mineral List 2026-07 Magnesiotaaffeite-2N'2S; Note: Current species name after the IMA-CNMNC 2001 renaming; the 2026-07 IMA list records it as Magnesiotaaffeite-2N'2S. |
| Magnesiotaaffeite-6N'3SEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | IMA Mineral List 2026-07 Magnesiotaaffeite-6N'3S; Note: Current species name after the IMA-CNMNC 2001 renaming; the 2026-07 IMA list records it as Magnesiotaaffeite-6N'3S. |
| MusgraviteEnglish | synonym | search candidate only | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.153 “Musgravite” |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- ターフェアイト族 (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)
- 塔菲石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Taaffeite-group minerals (IMA species: Magnesiotaaffeite-2N'2S, Magnesiotaaffeite-6N'3S, Ferrotaaffeite-2N'2S, Ferrotaaffeite-6N'3S); exact species requires advanced testing
- Trade names and synonyms
- Magnesiotaaffeite-2N'2S (narrower name (variety or subtype)) · Magnesiotaaffeite-6N'3S (narrower name (variety or subtype)) · Ferrotaaffeite-2N'2S (narrower name (variety or subtype)) · Ferrotaaffeite-6N'3S (narrower name (variety or subtype)) · Musgravite (synonym; conditional name)
Four-language names
- 简体中文
- 塔菲石族
- 繁體中文
- 塔菲石族
- English
- Taaffeite Group
- 日本語
- ターフェアイト族
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
- Mineral group / supergroup
- Mineral chemical class
- Oxides / hydroxides
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The composition (phase) of Taaffeite Group, as registered from the CIBJO list of gem materials, is Magnesiotaaffeite-2N’2S (gem name taaffeite) and Magnesiotaaffeite-6N’3S (gem name musgravite). The IMA naming status is Rn, meaning renamed: an existing mineral species renamed during the IMA period; both Magnesiotaaffeite-2N’2S and Magnesiotaaffeite-6N’3S, the species the original includes in this group, have IMA status Rn. This site notes that the CIBJO list of gem materials includes only Magnesiotaaffeite-2N’2S and Magnesiotaaffeite-6N’3S in the taaffeite group, listed under the gem names taaffeite and musgravite respectively; the cited IMA list also has iron-bearing species that the CIBJO list does not include. The original also records the colour of musgravite as greyish green and green, transparent, which applies only to the single species musgravite, not to the whole Taaffeite Group; where a gem name does not match a specific species, determining the species requires laboratory testing.
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”.
Definition
Taaffeite Group — nomenclature status: IMA status Rn: renamed (a mineral already known, given a new name in the IMA era).
CIBJO Gemmological Laboratories Book 2024
- Qualification
Both species the source lists for this group (magnesiotaaffeite-2N’2S and magnesiotaaffeite-6N’3S) have IMA status Rn.
Source & check 2026-09-28
- Source
- Fact checked on
- 2026-09-28
Taaffeite Group — composition (phase): magnesiotaaffeite-2N’2S (gem name taaffeite) and magnesiotaaffeite-6N’3S (gem name musgravite)
CIBJO Gemmological Laboratories Book 2024
- Qualification
CIBJO's gem materials list has only these two species of the group, listed under the gem names taaffeite and musgravite; the IMA list cited in the authority section also has iron-bearing species that CIBJO does not list. The source also gives musgravite as grey green to green and transparent, which describes that one species, not the whole group.
Where a gem name does not point to a particular species, identifying the species takes laboratory testing.
Source & check 2026-09-28
- Source
- Fact checked on
- 2026-09-28
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Testing and market
The CIBJO laboratory protocol covers Taaffeite Group under “Taaffeite” (§6.1.82): see identification on the Taaffeite entry; the required tests are listed on the CIBJO laboratory protocol table for Taaffeite.
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
The clause-level definition for Taaffeite Group is registered in the CIBJO Gemmological Laboratories Book 2024, under the entry Musgravite rather than the taaffeite group itself. As registered, Musgravite is a synonym of Magnesiotaaffeite-6N'3S, with a cross-reference to taaffeite, and the definition also records the colour of Musgravite as greyish green and green, transparent. The cross-check result is a direct CIBJO definition; no identically named English entry was found in this edition of the GB/T annex.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Musgravite | 7.2.1.153 | Musgravite is a synonym of Magnesiotaaffeite- 6N’3S (see also taaffeite) Grey green, green, transparent. See also taaffeite | Defined directly by CIBJO; no identically named English entry was found in this edition of 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.
- GIA – Gemological Institute of America (United States). Gem Encyclopedia.
- Gem-A – The Gemmological Association of Great Britain (United Kingdom).
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 |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Taaffeite Group 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.