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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Andradite
Also known asAndradite Garnet · Topazolite
A garnet-group mineral species with calcium and iron end-members; demantoid and melanite are its gem varieties. Also known as Andradite 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 Andradite 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 AndraditeHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of AndraditeThe enhancements and treatments the GB/T and JJA/AGL tables list
- Caring for and wearing AndraditeCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of AndraditeEach value with its source and check date
- Andradite 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 AndraditeThe listing name to use; what must be disclosed before sale
- Standard clauses that define AndraditeWhich 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
Numbers in curly braces, such as {111}, are crystallographic face symbols (Miller indices): each marks a set of crystal faces or cleavage planes. They are reproduced as written in the cited source.
Andradite is the calcium-iron member of the garnet group and counts among the five garnet species of commercial gem importance; demantoid is the green gem variety. Within Russia's Ural Mountains, Korkodin and Poldnevaya—the two deposits that currently yield demantoid in commercial amounts—occupy one and the same geological massif, which additionally contains abundant gold and platinum mineralisation. This species also mixes with grossular in a solid-solution series; research published recently identified, near the series midpoint between andradite and grossular, an orthorhombic garnet phase in which Fe-Al ordering is nearly complete, a finding that may bear on the iron-aluminium lamellae responsible for iridescent garnet.
Scope: Used to describe the composition, occurrence and solid solution of andradite as a calcium end-member mineral species of garnet; the source does not give specific formation temperatures, pressures or ages.
Sources GIA Garnet Description · G&G Spring 2018 · G&G Summer 2025
Where it forms
Deep massif hosting gold and platinum: the Ural demantoid deposits share a geological massif with gold and platinum mineralisations.
Sources G&G Spring 2018
Andradite-grossular solid solution: the setting for the alternating Fe- and Al-rich lamellae in iridescent garnet.
Sources G&G Summer 2025
How it forms, step by step
Andradite crystallizes in deep Fe-Ca-bearing massifs that may also host metal mineralisations.
Sources G&G Spring 2018
Andradite and grossular substitute across the series, potentially forming an intermediate phase with almost complete Fe-Al ordering.
Alternating Fe- and Al-rich lamellae parallel to {110} develop, producing iridescent (rainbow) andradite.
Link to appearance
Andradite can be green (demantoid); some stones show pink-to-blue iridescence from Fe-Al lamellae parallel to {110} (rainbow andradite).
Sources G&G Summer 2025
Timescale
The sources state no absolute age or duration for garnet formation.
Sources GIA Garnet Description · G&G Spring 2018 · G&G Summer 2025
Related base materials
- Garnet group: mineral-group member | Andradite is the calcic end-member mineral species dominated by Ca2+ and Fe3+; its green material is the demantoid variety
Supporting findings
The two Ural mines producing demantoid commercially (Korkodin and Poldnevaya) lie in the same geological massif, which also hosts gold and platinum mineralisations.
Evidence grade AScope: For the two current Ural production mines; not all andradite settings.
Sources G&G Spring 2018
An orthorhombic garnet phase with almost complete Fe-Al ordering was found in the middle of the andradite-grossular series, possibly related to iridescent garnet formation.
Evidence grade AScope: A recent study cited in a review; the authors note further work is needed on individual lamellae.
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Antetezambato mine, Ambanja, Diana, MadagascarDemantoid; Most gem rough was mined in 2009
Sources Mindat
- Tubussis, Erongo Region, NamibiaDemantoid; First significant demantoid locality outside Russia (mid-1990s)
Sources Mindat · Gems & Gemology Winter 2000
Asia
- Soghan, Arzuiyeh County, Kerman Province, IranDemantoid
Sources Mindat
- Belqeys Mountain, Takab County, West Azerbaijan Province, IranDemantoid; Rarely transparent; of limited gem interest
Sources Mindat
- Muslim Bagh, Balochistan, PakistanDemantoid; Crystals rarely over 1 cm; Peshawar is only the market
Sources Mindat
Europe
- Drammen, Buskerud, NorwayType locality of the species
Sources Mindat: Andradite
- Korkodin, Verkhny Ufaley, Chelyabinsk Oblast, RussiaDemantoid; Southern Ural locality; most Ural production now comes from this area
Sources Mindat
- Poldnevaya, Polevskoy, Sverdlovsk Oblast, RussiaDemantoid
Sources Mindat
- Near Nizhniy Tagil, Sverdlovsk Oblast, RussiaDemantoid; First discovery (placer gravel)
Sources Mindat
- Val Malenco (Lanzada), Sondrio, Lombardy, ItalyDemantoid; Little produced since the asbestos quarries closed in the 1970s
Sources Mindat
Seas and coasts
- WorldwideMindat lists 2,648 localities
Sources Mindat: Andradite
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
Andradite can show pink-to-blue iridescence (rainbow andradite), with lamellae parallel to {110} alternating between Fe-rich and Al-rich layers.
Evidence grade AScope: For iridescent andradite from specific localities; whether exsolution or growth is unclear.
Other research findings
Andradite is one of the five commercially important garnet species.
Evidence grade AScope: Defines it as a commercial species; no deposit detail.
Sources GIA Garnet Description
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- No absolute age, P-T or kinetics for andradite formation.
- The origin of the iridescent lamellae (exsolution vs. growth) is explicitly stated as unclear.
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
- Andradite
GB/T 16552—2017 Table A.1 “Andradite” · 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
Andradite is Andradite garnet; use "Andradite" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 钙铁榴石 (Andradite)
What this means for you
Before buying, check the recommended listing name "Andradite" 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 Andradite, is set out in full under care on the Garnet entry.
Care
Andradite — 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, Andradite, p.54; §6.2 e (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
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
HeatThe care conclusion recorded for Andradite is sensitivity to sudden temperature changes, in any treatment state, answering readers' questions on heat resistance and thermal shock; the source is the CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022). CleaningThe Gemological Institute of America (GIA) care and cleaning guide is given for the whole class, so it also applies to Andradite; its item-by-item advice is listed in full in the care section of the Garnet entry. General careGeneral care that applies to every gemstone in the CIBJO Gemstone Book, and the full table of special-care letters cited in care conclusions, are in the general care section of the materials index page.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Heat and thermal shock | care (heat) |
Treatments and identification leads
One row per treatment, with three standards side by side: how often it occurs and how stable it is (CIBJO), its category in GB/T 16552—2017 Table B.1 (this site's paraphrase) and how the JJA/AGL 2025 table lists it. Each CIBJO value links to its entry under “Testing and market”, where the wording and source are given in full.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| Heating | — | — | Optimization | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
“—” means the cited source gives no value for that item, not “none”. Source: 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
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Andradite, the name register records "Andradite Garnet" and "Topazolite", for which no restriction on use as a name is recorded (JJA/AGL Gemstone Nomenclature 2025 p.9; CIBJO Gemmological Laboratories Book 2024 §7.2.1.243 “Topazolite”); 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 formal name for Andradite is the name given in GB/T 16552—2017 Table A.1, and the suggested listing name is also Andradite, with the English description Andradite garnet. Names in four languagesThe four-language names are given in Simplified Chinese, Traditional Chinese, English (Andradite) and Japanese (a transliteration and a kanji name). Institution usageAmong authority wordings, CIBJO lists Andradite (CIBJO Gemmological Laboratories Book 2024); the FTC source text has no wording for this name (checked); GIA and Gem-A have not been checked, and bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe entry's own Japanese names are a transliteration and a kanji name; the Japanese GSJ wording for this name is not yet verified by this site. It is also called Andradite Garnet. Sub-names and unacceptable namesTopazolite is a subordinate name (variety or subtype), and the Japanese form of Andradite Garnet 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.
This table scrolls sideways on narrow screens.
| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (3) | ||||
| Andradite GarnetEnglish | synonym | matched automatically | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.9 |
| TopazoliteEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.243 “Topazolite” |
| アンドラダイト・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
- アンドラダイト／灰鉄柘榴石 (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 钙铁榴石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Andradite garnet
- Trade names and synonyms
- Topazolite (narrower name (variety or subtype)) · Andradite Garnet (synonym)
Four-language names
- 简体中文
- 钙铁榴石
- 繁體中文
- 鈣鐵榴石
- English
- Andradite
- 日本語
- アンドラダイト／灰鉄柘榴石
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 species
- 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 |
|---|---|---|---|---|
| Andradite Garnet | Andradite | brownish red, brownish green and others | 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
Registered material facts for Andradite: composition (phase) andradite (garnet group). The cited clauses give, for garnet (the whole mineral group): crystalline, cubic, with a rhombic dodecahedral or trapezohedral habit, or combinations of the two; Mohs hardness 7–8, no cleavage, optic character isotropic, commonly with anomalous extinction, and no birefringence. For andradite and demantoid, GB/T 16553—2017 gives a density clause value of 3.84 with a tolerance of ±0.03, from which the range 3.81–3.87 g/cm³ is worked out, and a refractive index clause value of 1.888 with a tolerance of +0.007, −0.033, from which the range 1.855–1.895 is worked out. The UV-visible spectrum shows a 440nm absorption band, possibly with absorption peaks at 618nm, 634nm, 685nm and 690nm. CIBJO registers transparency as transparent to opaque. For garnet (the whole mineral group), untreated, there is no pleochroism and the lustre is vitreous to subadamantine.
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 Andradite 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 Andradite (how to read class-level values).
Definition
Andradite — nomenclature status: IMA status G: grandfathered (described before the IMA existed, and generally regarded as a valid species).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Andradite — composition (phase): andradite (garnet group)
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Andradite — 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
Andradite — 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
Andradite — 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
Andradite — 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 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andradite — 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
Physical properties
Andradite — density: 3.81–3.87 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 3.84, with a stated tolerance of ±0.03. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Density · Andradite and demantoid (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Andradite — density: 3.5–4.3 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
- General note
- the clause has finer ranges
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
Optical
Andradite — 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
Andradite — refractive index: 1.855–1.895
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.888, with a stated tolerance of +0.007 / -0.033. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Refractive index · Andradite and demantoid (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Andradite — birefringence: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- garnet (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andradite — transparency: transparent to opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Andradite — 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
Andradite — 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.
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
Andradite — 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
Andradite — 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
Andradite — magnification: horsetail inclusions
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): §5.1.15 Magnification (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
body colour2 sources compared
Andradite — body colour: Yellow, green, brown, black.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Serpentine, Actinolite, Chrysoberyl and other entries also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Andradite — 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 list essentially the same colours: yellow, green, brown and black; GB/T 16553—2017 runs the last two together as brownish black.
- CIBJO definitions
- asterism, colour change
Quality factors
Andradite — 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): 1.875 / 3.9; Closest values: 1Demantoid 1.89 / 3.84, 2Uvarovite 1.85 / 3.9, 3Garnet 1.825 / 3.9, 4Spessartine 1.802 / 3.9, 5Almandine 1.79 / 3.9
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
The CIBJO laboratory protocol covers Andradite under “Garnet”: for identification see the Garnet entry, and the required tests are listed on the laboratory testing page. As for synthetics, no synthetic counterpart of Andradite is commercially available.
The CIBJO laboratory protocol covers Andradite 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
Andradite — 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
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Andradite has a direct definition in the CIBJO Gemmological Laboratories Book 2024 under the term Andradite: mineral group garnet, mineral species andradite, IMA status G, with the CIBJO wording quoted in full under Clause-level definitions on this page. CIBJO also gives a direct definition for Topazolite, a yellow, transparent to translucent andradite that may show chatoyancy; the cross-check result is a direct CIBJO definition, with no identically named English entry found in the GB/T annex. The IMA Mineral List entry records Andradite with the formula Ca3Fe3+2(SiO4)3, IMA status G and the year 1868, cross-checked against the RRUFF/IMA master mineral list (public domain data). The cross-check result for Andradite is a direct CIBJO definition, also present in the GB/T annex.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Andradite | 7.2.1.17 | Yellow, green, brown, black, transparent to opaque; see demantoid, melanite, topazolite | Defined directly by CIBJO; also present in the GB/T annex. |
| Topazolite | 7.2.1.243 | Yellow, transparent to translucent andradite; may show chatoyancy | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Andradite | IMA Mineral List entry | Andradite Ca3Fe3+2(SiO4)3 G 1868 | Cross-checked against the RRUFF/IMA master mineral list (public domain data). |
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.
This table scrolls sideways on narrow screens.
| 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 Andradite 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.