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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
Andalusite
A silicate mineral species listed in GB/T 16552-2017 Appendix A.1; its colour and pleochroism cannot serve as proof of origin or treatment. 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 Andalusite forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify AndalusiteHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Andalusite1 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing AndalusiteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of AndalusiteEach value with its source and check date
- Andalusite 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?
- Name origin and history of AndalusiteWhere the name comes from
- Listing and disclosing AndalusiteThe listing name to use; what must be disclosed before sale
- Standard clauses that define AndalusiteWhich 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
Andalusite has the formula Al2SiO5 and is one of the three Al2SiO5 polymorphs, sharing its composition with kyanite and sillimanite but differing in crystal structure; it also forms a series with the manganese end member kanonaite. It is a classic product of contact (low-pressure, high-temperature) metamorphism of argillaceous sediments, and also occurs in regionally metamorphosed schists. It is rare in granites and pegmatites, which however yield the largest crystals, and occurs as a detrital mineral in some sandstones. A carbon-bearing cruciform variety, chiastolite, is also known.
Scope: Applies to the genesis, composition and occurrence of andalusite as the low-pressure, high-temperature polymorph of Al2SiO5, including the variety boundary of chiastolite; does not cover synthetic materials.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Where it forms
Contact (low-pressure, high-temperature) metamorphism of argillaceous sediments
Sources Handbook of Mineralogy
Schists formed by regional metamorphism
Sources Handbook of Mineralogy
Granites and pegmatites (rare, but yield the largest crystals); detrital in some sandstones
Sources Handbook of Mineralogy
How it forms, step by step
Aluminium-rich argillaceous sediments are heated near an intrusion, undergoing contact (low-pressure, high-temperature) metamorphism.
Sources Handbook of Mineralogy
Under those conditions Al2SiO5 crystallizes with the andalusite structure rather than as kyanite or sillimanite.
Sources Handbook of Mineralogy
Andalusite commonly forms columnar crystals or aggregates with nearly square cross sections, up to 20 cm.
Sources Handbook of Mineralogy
In carbon-rich varieties, cruciform carbonaceous inclusions form the chiastolite habit.
Sources Handbook of Mineralogy
Link to appearance
Andalusite may be pink, violet, yellow, green, white or grey, with a vitreous to subvitreous luster and weak pleochroism; chiastolite is characterized by its carbonaceous cross pattern.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Timescale
The sources state no timescale for andalusite formation.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Supporting findings
Andalusite results from contact (low-pressure, high-temperature) metamorphism of argillaceous sediments and also occurs in regionally metamorphosed schists; it is rare in granites and pegmatites (which yield the largest crystals) and is detrital in some sandstones.
Evidence grade BScope: Describes andalusite's metamorphic occurrence; it does not extend to quantified stability fields of the polymorphs.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Nawalapitiya, Sri LankaGood-crystal locality; not stated as gem-grade
Sources Handbook of Mineralogy
Europe
- El Cardoso de la Sierra, Guadalajara, SpainNamed after Andalusia in error; the type locality is El Cardoso
Sources Mindat: Andalusite
South America
- Santa Teresa district, Espírito Santo, BrazilListed as a source of gem crystals
Sources Handbook of Mineralogy
Seas and coasts
- WorldwideWidespread mineral
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.
Where the name comes from
The English name andalusite is named after an occurrence in the Andalusia region, Spain.
Evidence grade BScope: Etymology explains the origin of the name only; it does not establish the material's composition, locality, naturalness, or treatment.
Sources Handbook of Mineralogy
Other research findings
Andalusite has the formula Al2SiO5 and is trimorphous with kyanite and sillimanite, and forms a series with kanonaite.
Evidence grade BScope: Describes andalusite's composition and polymorphism; it gives no stability-field numbers among the polymorphs.
Sources Handbook of Mineralogy
Andalusite shares its composition with kyanite and sillimanite but differs in structure, and is the stable aluminium-silicate phase under low-pressure, high-temperature contact-metamorphic conditions.
Evidence grade BScope: Defines andalusite's polymorphic relationship with the other two Al2SiO5 polymorphs; not for phase-diagram numbers of the three.
Sources Handbook of Mineralogy
Chiastolite is the carbon-rich, cruciform variety of andalusite, listed as a distinct variety of andalusite in the CIBJO nomenclature.
Evidence grade AScope: Defines chiastolite's variety-to-species relationship with andalusite; it does not treat chiastolite as an independent species.
Sources CIBJO Gemstone Book 2022
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The sources state no absolute geological timescale for andalusite formation.
- The available sources give no P-T values for the stability fields of andalusite, kyanite and sillimanite, only a qualitative statement that andalusite is a contact-metamorphic product.
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
- Andalusite
GB/T 16552—2017 Table A.1 “Andalusite” · IMA Mineral List 2026-07 “Andalusite”
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Heated / Heat-treated
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
Andalusite is Andalusite; use "Andalusite" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 红柱石 (Andalusite)
What this means for you
Before buying, check the recommended listing name "Andalusite" 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
Care
Andalusite — care (cleaning): ultrasonic: relatively safe; steamer: use caution.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Andalusite row, CLEANING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andalusite — care (special care): normal care
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.VII, Gemstone Information Chart, Andalusite N, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andalusite — care (setting): prong and bezel: use caution; flush, channel and pavé: avoid; note: one distinct cleavage.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Andalusite row, SETTING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andalusite — care (repair): polishing: relatively safe; thermal shock: use caution; pickle pot: use extreme caution; jeweller's torch: avoid; note: heat-sensitive when liquid inclusions are present.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Andalusite row, REPAIR column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andalusite — care (display): heat in the display case, sunlight and artificial light: relatively safe.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Andalusite row, DISPLAY column (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
All registered care conclusions for Andalusite specify the untreated state. CleaningFor cleaning, Martin, Gemstone Durability: Design to Display, states that ultrasonic cleaning of untreated Andalusite is relatively safe and steam cleaning needs caution; the AGTA Gemstone Information Manual, 17th edition, states that untreated Andalusite needs only general care. Repair and heatFor repair and heat, Martin states that polishing untreated Andalusite is relatively safe, thermal shock needs caution, the pickle pot needs extreme caution and the jeweller's torch should be avoided, noting that it is heat-sensitive when liquid inclusions are present. SettingFor setting, prong and bezel settings for untreated Andalusite need caution, while tension, channel and pavé settings should be avoided; Martin also notes that Andalusite has one distinct cleavage. Display, heatFor display, heat, sunlight and artificial light in the display case are relatively safe for untreated Andalusite.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | ultrasonic: relatively safe; steamer: use caution |
| Heat and thermal shock | polishing: relatively safe; thermal shock: use caution; pickle pot: use extreme caution; jeweller's torch: avoid; note: heat-sensitive when liquid inclusions are present |
| Light and display | heat in the display case, sunlight and artificial light: relatively safe |
| Wearing limits (knocks, settings) | prong and bezel: use caution; flush, channel and pavé: avoid; note: one distinct cleavage |
Durability and wearing
Toughness
Brittle
Fracture
Uneven to subconchoidal
Sources Handbook of Mineralogy
Treatments and identification leads
Registered treatmentsThe registered treatment for Andalusite is heating, with the status treated. Values not givenThe stability and prevalence of heating are both recorded as “—”, meaning the cited source gives no value, not “none”. Identification cluesThe identification lead for heating is that some green Andalusite turns pink on heating; the colour is stable and difficult to detect. The source of the identification lead is GB/T 16553—2017.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| heatingStatus: treated | — | — | Optimization | — | See identification leads |
Where each treatment acts (schematics): Heated / Heat-treated
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16553—2017; GB/T 16552—2017 Table B.1
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
Chinese standard nameThe Chinese formal name for Andalusite comes from GB/T 16552—2017 Table A.1; the mineralogical name is Andalusite, and the GSJ (Japan) formal name is the Japanese name for andalusite. Names in four languagesThe four-language names cover Simplified Chinese, Traditional Chinese, English ("Andalusite") and Japanese. Recommended listing nameThe suggested listing name is "Andalusite". Institution usageOn authority wording, among GIA, FTC, CIBJO and Gem-A, this site has recorded only the CIBJO wording, Andalusite, from the CIBJO Gemmological Laboratories Book 2024; the FTC text has no wording for Andalusite (checked); 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.
- GSJ (Japan) formal name
- 紅柱石
- Chinese formal name
- 红柱石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Andalusite
Four-language names
- 简体中文
- 红柱石
- 繁體中文
- 紅柱石
- English
- Andalusite
- 日本語
- アンダルサイト／紅柱石
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
- Mineral species
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
In GB/T 16552—2017 Annex B, Table B.1, the “Andalusite” row lists heating, with the effect of improving colour, classed as optimization. What Table B.1 notes and how each grade is defined are explained on this site's Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Table B.1, row “Andalusite” (p.15):
This table scrolls sideways on narrow screens.
| Method | Effect | Category |
|---|---|---|
| Heating | Improves colour | Optimization |
What Table B.1 is, and how the “see 5.4.1” grades are defined: see the GB/T 16552: optimization vs treatment page.
What it is and how it's identified
Registered material facts for Andalusite: the chemical composition is Al2SiO5, which may contain elements such as V, Mn, Ti and Fe; the structure is crystalline and orthorhombic, with a prismatic crystal habit. Mohs hardness is 7–7.5, with one set of moderate cleavage; this site notes that hardness alone is not enough to judge durability. Density is 3.13–3.21 g/cm³; the cited clause gives 3.17 with an allowed deviation of ±0.04, from which the limits are derived. Optically, andalusite is anisotropic, biaxial and optically negative; the refractive index is 1.629–1.648, the cited clause giving 1.634–1.643 with an allowed deviation of ±0.005, from which the limits are derived; birefringence is 0.007–0.013. Untreated andalusite shows strong trichroism in brownish yellow-green, brownish orange and brownish red, with a vitreous lustre.
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
Andalusite — 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
Andalusite — composition (chemistry): Al2SiO5, elements such as V,Mn,Ti and Fe may be contained.
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — composition (phase): andalusite
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Andalusite — structure (overall): crystalline
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — structure (crystal system): orthorhombic
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — structure (crystal habit): columnar
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Andalusite — Mohs hardness: 7–7.5
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
- General note
- hardness only, not durability
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — cleavage: moderate in one direction
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Physical properties
Andalusite — density: 3.13–3.21 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 3.17, with a stated tolerance of ±0.04. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Andalusite — optic character: biaxial, optically negative (anisotropic)
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — refractive index: 1.629–1.648
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.634–1.643, with a stated tolerance of ±0.005. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — birefringence: 0.007–0.013
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — transparency: transparent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Andalusite — pleochroism: Trichroism is strong: brownish orange, brownish red and brownish yellow-green.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — fluorescence (long-wave UV): none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — fluorescence (short-wave UV): none to moderate, green to yellow-green
GB/T 16553—2017
UV fluorescence (short-wave UV)greenyellow-greennone–moderateDots are illustrative colours built from the colour names, not measured values
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — spectrum (UV-visible): green, pale red, brown-red: weaker 436 nm absorption peak; weaker 445 nm absorption peak.
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — spectrum (infrared): In the mid-IR, andalusite shows its own diagnostic band pattern.
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): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — magnification: gas-liquid inclusions, mineral inclusions, needle inclusions, the chiastolite variety has black carbonaceous inclusions distributed in a cross.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
body colour2 sources compared
Andalusite — body colour: yellowish green, yellowish brown; green, brown, pink and similar colours may also occur; purple is rare. Stones with a black cross inside are called chiastolite.
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 Rhodonite, Zoisite, Rock Crystal and other variety clauses also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andalusite — body colour: Brownish or yellowish green to orangish brown.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Canary Tourmaline, Mali Garnet, Sphalerite and other entries also name brown or a brownish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
How the sources relate
- GB/T 16553—2017 and CIBJO Gemmological Laboratories Book 2024
Both describe the yellowish green to brown range (the CIBJO Gemmological Laboratories Book gives brownish or yellowish green to orangish brown). GB/T 16553—2017 also lists pink, the rare purple, and chiastolite with its black cross.
Quality factors
Andalusite — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
This material (RI / SG midpoints): 1.639 / 3.17; Closest values: 1Lazulite 1.627 / 3.12, 2Sillimanite 1.668 / 3.21, 3Actinolite 1.627 / 3.03, 4Euclase 1.663 / 3.06, 5Danburite 1.633 / 3
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
Heat treatment of Andalusite can be recognised from the fact that some green Andalusite turns pink on heating, with a stable colour that is hard to detect; this applies to treated stones. GB/T 16553—2017 can only be used as a reference for Andalusite and does not govern it directly. No synthetic counterpart of Andalusite is available on the market. The CIBJO laboratory protocol (Gemmological Laboratories Book 2024) notes a special optical effect, chatoyancy, for Andalusite testing methods; the required tests and what each method means are in the protocol table on the laboratory testing page.
The tests the CIBJO laboratory protocol requires for this material, and what each method means, are in the protocol table on the laboratory testing page: §6.1.6.
How far testing can go
Andalusite that has undergone heating can be identified by the following features: Heating some green andalusite produces pink; the result is stable and not easy to detect.
GB/T 16553—2017
- Treatment state
- treated
- Does this standard apply
- can be followed as a reference only
- Treatment
- heating
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.26 (heating) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andalusite — 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
Andalusite — notes on test methods in the CIBJO laboratory protocol:
| Test method | What the protocol notes for it |
|---|---|
| Phenomena: | Cat’s-eye |
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- 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.
Clause-level definitions
Andalusite is defined directly in CIBJO Gemmological Laboratories Book 2024 under the entry name Andalusite, as mineral species andalusite with IMA status G, noting that the CIBJO wording is quoted in full under Clause-level definitions on this page; the cross-check result is that it is defined directly by CIBJO and also appears in the GB/T annex. Andalusite is also registered from the IMA Mineral List entry, which reads Andalusite Al2SiO5 G 1798, cross-checked against the RRUFF/IMA master mineral list; this is public domain data.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Andalusite | 7.2.1.15 | Brownish or yellowish green to orangish brown, transparent (both green and orange are often visible because of strong pleochroism) | Defined directly by CIBJO; also present in the GB/T annex. |
| Andalusite | IMA Mineral List entry | Andalusite Al2SiO5 G 1798 | 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.
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| Page | Content | Status |
|---|---|---|
| Browsing family | Other silicate minerals | Live |
| Treatments recorded for this material | Heated / Heat-treated | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Andalusite 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.