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
Demantoid
Also known asDemantoid garnet
The green gem variety of Andradite, listed as Demantoid in GB/T 16552—2017 Table A.1; it is not a general name for green Garnet. 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 Demantoid 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 DemantoidHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Demantoid1 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing DemantoidCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of DemantoidEach value with its source and check date
- Demantoid 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 DemantoidThe listing name to use; what must be disclosed before sale
- Standard clauses that define DemantoidWhich 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
Demantoid is not a mineral species in its own right but the green gem form of andradite garnet. It was first discovered in Russia's Central Urals during the mid-1800s. Today independent miners there extract appreciable volumes of stream-rounded demantoid pebbles from two principal districts—Nizhniy Tagil, roughly 115 km to the north, and Sissertsk, some 75 km to the south, both relative to Ekaterinburg. Within the Urals, the Korkodin and Poldnevaya workings—the two mines now producing the material commercially—share a single geological massif that is also endowed with gold and platinum mineralisation. A diagnostic feature is the horsetail inclusion, an outward-radiating pattern of asbestos fibres.
Scope: Used to describe the localities and inclusion features of demantoid as the green variety of andradite; the source does not give its formation temperatures, pressures or ages.
Sources G&G Summer 1996 · G&G Spring 2018
Where it forms
Russian Ural massif hosting gold and platinum: the commercial demantoid mines (Korkodin, Poldnevaya) lie in the same geological massif that hosts gold and platinum mineralisations.
Sources G&G Spring 2018
Fluvial placer setting: at Nizhniy Tagil and Sissertsk, miners recover stream-worn demantoid pebbles.
Sources G&G Summer 1996
How it forms, step by step
Green andradite (demantoid) crystallizes in the iron- and calcium-bearing, metal-mineralised rocks of the Urals.
Sources G&G Spring 2018
Radiating aggregates of asbestos fibres develop inside the crystals, forming the typical horsetail inclusion.
Sources G&G Spring 2018
Some crystals are weathered, transported and stream-rounded, becoming the pebbles recovered by miners.
Sources G&G Summer 1996
Link to appearance
Demantoid covers all shades of green; the finest is a pure, vibrant green with no secondary hue. Some material is brownish (common at Korkodin) and can be heat-treated to remove the brown. The horsetail inclusion is a diagnostic feature.
Sources G&G Spring 2018
Timescale
The sources state no absolute age or duration for garnet formation.
Sources G&G Summer 1996 · G&G Spring 2018
Related base materials
- Andradite garnet: variety-of | Demantoid is the green gem variety of andradite, not a separate mineral species
Supporting findings
Notable amounts of stream-worn demantoid pebbles are being extracted by independent miners across two principal districts: Nizhniy Tagil, some 115 km to the north, and Sissertsk, roughly 75 km to the south, both measured from Ekaterinburg.
Evidence grade AScope: Describes the two main Ural placer districts as reported in 1996.
Sources G&G Summer 1996
Both of the Ural mines that presently produce demantoid on a commercial scale sit within one geological massif, which is additionally rich in gold and platinum mineralisation.
Evidence grade AScope: For the Korkodin and Poldnevaya mines as reported in 2018.
Sources G&G Spring 2018
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Antetezambato mine, Ambanja, Diana, MadagascarMost gem rough was mined in 2009
Sources Mindat
- Tubussis, Erongo Region, NamibiaFirst significant demantoid locality outside Russia (mid-1990s)
Sources Mindat · Gems & Gemology Winter 2000
Asia
- Soghan, Arzuiyeh County, Kerman Province, Iran
Sources Mindat
- Belqeys Mountain, Takab County, West Azerbaijan Province, IranRarely transparent; of limited gem interest
Sources Mindat
- Muslim Bagh, Balochistan, PakistanCrystals rarely over 1 cm; Peshawar is only the market
Sources Mindat
Europe
- Korkodin, Verkhny Ufaley, Chelyabinsk Oblast, RussiaSouthern Ural locality; most Ural production now comes from this area
Sources Mindat
- Poldnevaya, Polevskoy, Sverdlovsk Oblast, Russia
Sources Mindat
- Near Nizhniy Tagil, Sverdlovsk Oblast, RussiaFirst discovery (placer gravel)
Sources Mindat
- Val Malenco (Lanzada), Sondrio, Lombardy, ItalyLittle produced since the asbestos quarries closed in the 1970s
Sources Mindat
- Babrovka River valley, Ekaterinburg area, RussiaBoth the original locality and new deposits (Karkodino) produced
Sources Gems & Gemology Winter 2000
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
Demantoid covers all shades of green; the finest is a pure vibrant green without secondary hue, while Korkodin material commonly carries a brownish tint removable by heating.
Evidence grade AScope: Quality/colour description, not a formation mechanism; no specific chromophore data.
Sources G&G Spring 2018
Other research findings
The green variety of andradite garnet is called demantoid; its discovery dates to the mid-1800s in Russia's Central Urals.
Evidence grade AScope: Defines its rank as a variety and its discovery locality; not an independent species.
Sources G&G Summer 1996
The horsetail inclusion—an asbestos-fibre pattern that radiates outward—is characteristic of demantoid.
Evidence grade AScope: Typical of Russian demantoid; other localities have it but matter less.
Sources G&G Spring 2018
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- No absolute age, P-T or quantitative chromophore data for demantoid formation.
- Locality/feature description is Ural-focused and not global.
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
- Demantoid
GB/T 16552—2017 Table A.1 “Demantoid” · IMA Mineral List 2026-07 “Andradite”
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Heated / Heat-treated (via parent material), Filled / Fracture-filled (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
Demantoid is Green andradite gem variety; use "Demantoid" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 翠榴石 (Demantoid)
What this means for you
Before buying, check the recommended listing name "Demantoid" 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 Demantoid, is set out in full under care on the Garnet entry.
Care
Demantoid — care (heat): Some stones are prone to damage due to thermal shock. Do not expose them to extreme temperature changes.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code e
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Demantoid, p.54; §6.2 e (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Demantoid — care (special care): heated for colour: normal care, but avoid sudden temperature change.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- heating
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.X, Gemstone Information Chart, Garnet Demantoid H, 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.
Common care questions and matching entries
Heat-related care for Demantoid is clearly recorded. The Demantoid entry in the CIBJO Gemstone Book (Coloured Stone Commission, 2022) states that Demantoid is sensitive to sudden temperature changes, irrespective of treatment status. The AGTA Gemstone Information Manual, 17th edition, states that Demantoid heated to improve colour needs only normal care but should be kept away from sudden temperature changes; the AGTA statement on heating to improve colour applies to treated stones and covers heat treatment only.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Heat and thermal shock | care (heat) |
Care entries by treatment state
The same entries grouped by the treatment state each applies to; each links to its full wording and source. Letters are CIBJO special-care codes, explained on the gemstone care page.
any treatment state
- care (heat) §6.2 e
treated (Only after these treatments: heating)
Treatments and identification leads
Registered treatmentsThe treatment registered for Demantoid is heating, with status treated, stability stable and market prevalence common. Values not givenThe identification leads and source for heating are both given as "—", meaning the cited source gives no corresponding value, not "none". SyntheticsThere is no synthetic Demantoid on the market.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| heatingStatus: treated | commonly | stable | Optimization | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
Where each treatment acts (schematics): Heated / Heat-treated
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022; GB/T 16552—2017 Table B.1 (row for Garnet); 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
How lab reports word it
A general LMHC wording rule also covers Demantoid (Information Sheet #8): see the LMHC rule “When colour authenticity cannot be determined”.
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Demantoid, the name register records "Demantoid garnet", for which no restriction on use as a name is recorded; 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).
Standard and listing namesThe Chinese formal name of Demantoid comes from GB/T 16552—2017 Table A.1; the common trade name/synonym is Demantoid garnet, and the suggested listing name is Demantoid. Names in four languagesFour-language names are given in Simplified Chinese, Traditional Chinese, English (Demantoid) and Japanese. Institution usageOn authority wording, CIBJO Gemmological Laboratories Book 2024 records Demantoid; the FTC text on file has no wording for this name (checked); GIA and Gem-A are unchecked; bodies without a recorded or verified wording show the English name Demantoid, which does not represent their position. Japanese namesThe entry has its own Japanese name for Demantoid, and the wording of Japan's GSJ for it is not yet verified by this site. Candidate search termsThe Japanese form of demantoid garnet registered in the JJA/AGL gem name handbook 2025 is kept only as a candidate search term. Trade and mineralogical namesThe mineralogical name refers to the green andradite gem 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.
This table scrolls sideways on narrow screens.
| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (2) | ||||
| Demantoid garnetEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| デマントイド・ガーネットJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.9 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- デマントイド (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 翠榴石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Green andradite gem variety
- Trade names and synonyms
- Demantoid garnet (market name)
Four-language names
- 简体中文
- 翠榴石
- 繁體中文
- 翠榴石
- English
- Demantoid
- 日本語
- デマントイド
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Garnet-group minerals and gem varieties
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
GB/T 16552-2017, Annex B, Table B.1
Under the “Garnet” row of Table B.1: Heating Optimization; Filling Graded — see §5.4.1, Table 1. The full row, with the effect column, is on the Garnet 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 |
|---|---|---|---|---|
| Demantoid Garnet | Andradite | green to yellowish green (chromium, with or without iron) | an untreated tier is listed |
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
Demantoid is the chromium-bearing variety of andradite. The CIBJO Blue Book registers the composition (phase) of Demantoid as andradite (garnet group). Registered from the cited clauses for garnet (the whole mineral group), the structure of Demantoid is crystalline and cubic, with a crystal habit of rhombic dodecahedra or trapezohedra, or combinations of the two; Mohs hardness is 7–8 and there is no cleavage; the optic character is isotropic, commonly with anomalous extinction, and there is no birefringence; when untreated, the quality factor (lustre) is vitreous to subadamantine. Density is 3.81–3.87 g/cm³. The refractive index is 1.89; this site notes that the cited clause combines andradite and Demantoid under the refractive index item, giving a value of 1.888 (+0.007/−0.033), which differs from the 1.89 in the additional note. The UV-visible spectrum shows an absorption band at 440nm, possibly with absorption peaks at 618nm, 634nm, 685nm and 690nm, and a chromium absorption peak at 701nm.
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 garnet (the whole mineral group), so they are not repeated on the Demantoid page; see the material facts on the Garnet entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Demantoid (how to read class-level values).
Definition
Demantoid: the chromium-bearing variety of andradite
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Additional notes (locator checked 2026-09-28)
- Fact checked on
- 2026-09-21
Demantoid — composition (phase): andradite (garnet group)
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Demantoid — structure (overall): crystalline
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Demantoid — structure (crystal system): cubic
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Demantoid — structure (crystal habit): rhombic dodecahedra, tetragonal trisoctahedra, or crystals combining the two forms.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Demantoid — Mohs hardness: 7–8
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
- garnet (the whole mineral group)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Demantoid — cleavage: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
For Demantoid, the stability of heating is “stable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- heating
- Qualification
This says how well the treatment holds up, not how durable Demantoid itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Physical properties
Demantoid — density: 3.81–3.87 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Additional notes (locator checked 2026-09-28)
- Fact checked on
- 2026-09-21
Optical
Demantoid — optic character: isotropic, commonly with anomalous extinction
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Demantoid — refractive index: 1.89
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
In its refractive-index field the same clause gives andradite and demantoid together as 1.888 (+0.007 / -0.033), which is written differently from the 1.89 in its additional note.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Additional notes (locator checked 2026-09-28)
- Fact checked on
- 2026-09-21
Demantoid — birefringence: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Demantoid — pleochroism: none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Demantoid — spectrum (UV-visible): andradite and demantoid: 440 nm absorption band; may have 618 nm absorption peak; may have 634 nm absorption peak; may have 685 nm absorption peak; may have 690 nm absorption peak; 701 nm absorption peak due to chromium.
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): §5.1.15 UV-visible spectrum (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Demantoid — optical effect (asterism): seen; rare; generally a four-pointed star; occasionally a six-rayed star (almandine).
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Demantoid — optical effect (colour change): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
body colour2 sources compared
Demantoid — body colour: Green to yellow green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Chrysoprase, Green Quartz, Prehnite and other entries also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Demantoid — body colour: yellow, green, brownish black
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- Qualification
In chapter 5 of GB/T 16553—2017, the colour entries of Epidote, Serpentine, Peridot and other variety clauses also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Colour · Andradite and demantoid (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
How the sources relate
- CIBJO Gemmological Laboratories Book 2024 and GB/T 16553—2017
The two entries cover different ranges: GB/T 16553—2017 gives andradite and demantoid together (yellow, green, brownish black), while the CIBJO Gemmological Laboratories Book describes demantoid alone (green to yellow green). They agree on green and yellow.
- CIBJO definitions
- asterism, colour change
Quality factors
Demantoid — quality factor (lustre): vitreous to subadamantine
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (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): 1.89 / 3.84; Closest values: 1Andradite 1.875 / 3.9, 2Uvarovite 1.85 / 3.9, 3Garnet 1.825 / 3.9, 4Spessartine 1.802 / 3.9, 5Titanite / Sphene 1.967 / 3.52
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
In the CIBJO laboratory protocol, Demantoid is listed under “Garnet”; for identification, see the identification section of the Garnet entry, and for the list of required tests, see the laboratory testing page. No synthetic Demantoid is available on the market. Among Demantoid in trade, heating occurs commonly.
The CIBJO laboratory protocol covers Demantoid under “Garnet” (§6.1.38): see identification on the Garnet entry; the required tests are listed on the CIBJO laboratory protocol table for Garnet.
How far testing can go
Demantoid — 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 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Demantoid in trade, the reported frequency of heating is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- heating
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Demantoid is listed in the CIBJO Gemmological Laboratories Book 2024 under the entry Demantoid, defined as the green to yellowish green variety of andradite. The cross-check result is: defined directly by CIBJO, and also appears in the GB/T annex.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Demantoid | 7.2.1.71 | Green to yellow green variety of andradite | 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 Garnet on this site: 10 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Demantoid) is marked.
- Garnet
Sub-entries (9)
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| Page | Content | Status |
|---|---|---|
| Browsing family | Garnet-group minerals and gem varieties | Live |
| Treatments recorded for this material | Heated / Heat-treated (via parent material), Filled / Fracture-filled (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Demantoid 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.