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
Indicolite
Also known asBlue Tourmaline · Indigolite
A gem variety name for blue Tourmaline, ranging in tone from light blue to deep blue-green; any treatment must be disclosed. Also known as Indigolite. 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 Indicolite 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 IndicoliteHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Indicolite3 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing IndicoliteCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of IndicoliteEach value with its source and check date
- Indicolite 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 IndicoliteThe listing name to use; what must be disclosed before sale
- Standard clauses that define IndicoliteWhich 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
Blue tourmaline is not an independent mineral species but a blue colour variety of tourmaline (mostly elbaite), traded as indicolite. Its blue to bluish green colour is generally attributed to iron (and possibly titanium); copper-bearing blue-to-green tourmaline (the Paraíba type) is coloured by Cu2+, often accompanied by Mn, and Cu2+ shows a characteristic absorption band near 900–925 nm that distinguishes it from the ~700 nm Fe2+ band. The parent material forms in granite-bearing pegmatites, with crystals growing mostly in open pockets of the pegmatite core zone.
Scope: Applies to explaining the colouration and occurrence of natural blue to blue-green tourmaline colour varieties; not applicable to synthetics, treated material or determining the locality of a specific sample.
Sources GIA Tourmaline Description · G&G Summer 2025
Where it forms
Granite-bearing pegmatites; crystals occur mostly in open (or clay-filled) pockets of the pegmatite core zone.
Sources GIA Tourmaline Description · G&G Summer 2025
Different pockets, or even one pocket, can yield tourmaline crystals of very different colours.
Sources GIA Tourmaline Description · G&G Summer 2025
How it forms, step by step
A volatile- and rare-element-rich residual magmatic fluid crystallises within the pegmatite body, and tourmaline (elbaite) begins to grow.
Sources GIA Tourmaline Description · G&G Summer 2025
Trace elements such as iron (and possibly titanium, or copper and manganese) enter the lattice, producing blue to bluish green colour.
Sources GIA Tourmaline Description · G&G Summer 2025
Where copper-bearing fluids are involved, Cu2+ becomes the blue-to-green chromophore, forming Paraíba-type blue-green tourmaline.
Sources GIA Tourmaline Description · G&G Summer 2025
Link to appearance
Blue to greenish blue can be caused by iron (with or without titanium) or by copper; the Cu2+ band near 900–925 nm is distinguishable from the ~700 nm Fe2+ band, so visually similar blue tourmalines require spectroscopy to resolve the colouring element.
Sources GIA Tourmaline Description · G&G Summer 2009
Timescale
The cited sources give no absolute timescale for blue tourmaline formation.
Sources GIA Tourmaline Description · G&G Summer 2025
Related base materials
- Tourmaline group (mostly elbaite): colour variety of tourmaline; indicolite
Supporting findings
Overall, blue tourmaline forms as elbaite crystallising in granite-bearing pegmatites, where trace Fe (±Ti, ±Cu) enters the lattice to give the blue colour, with crystals growing mostly in core-zone pockets.
Evidence grade BScope: A multi-source synthesis; the pegmatite setting is the general case, and chromophore proportions vary with specimen and locality.
Sources GIA Tourmaline Description · G&G Summer 2025
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- NamibiaBlue-green.
Sources Gems & Gemology Winter 2000
Asia
- Afghanistan
Sources Gems & Gemology Winter 2000
South America
- Cruzeiro mine, Minas Gerais, Brazil
Sources Gems & Gemology Summer 1985
- Paraíba, BrazilCopper-bearing Paraíba tourmaline.
Sources Gems & Gemology Winter 2000 · GIA Tourmaline Description
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
Tourmaline colour has many causes; traces of iron, and possibly titanium, are generally agreed to induce green and blue colours.
Evidence grade AScope: A general statement on tourmaline colouring as a whole, not specific to blue tourmaline and not quantifying each element's contribution.
Sources GIA Tourmaline Description
In copper-bearing tourmaline, Cu2+ is the chromophore for blue-to-green, with a band near 900–925 nm distinguishable from the ~700 nm Fe2+ band, allowing copper vs. iron colourants to be told apart.
Evidence grade AScope: Applies to distinguishing copper from iron as colourants; it does not determine origin and does not extend to copper-free tourmaline.
Other research findings
Indicolite refers to dark violetish blue, blue, or greenish blue tourmaline; it is a colour variety, not an independent mineral species.
Evidence grade AScope: Defines the trade colour range only; it cannot establish a specimen's species, treatment, or origin.
Sources GIA Tourmaline Description
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The cited sources give no absolute timescale for blue tourmaline formation.
- No quantitative share of each colouring element in blue is given; Paraíba-type copper tourmaline raises separate origin and treatment issues needing other 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
- Indicolite (blue tourmaline)
16 CFR Part 23 §23.24
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Heated / Heat-treated, Filled / Fracture-filled (via parent material), Dyed (via parent material), Irradiated (via parent material), Coated (via parent material)
Related:Disclosure and cautions
This page cannot answer
Natural? · Origin · Price
A lab report settles these; this wiki covers naming and disclosure.
Related:What this page can answer
Answer at a glance
Indicolite is Blue tourmaline gem variety; use "Indicolite (blue tourmaline)" for listings, and disclose any known treatments.
Evidence
What this means for you
Before buying, check the recommended listing name "Indicolite (blue tourmaline)" 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 Indicolite, is set out in full under care on the Tourmaline entry.
Care
Indicolite — care (cleaning): Some stones are susceptible to damage from ultrasonic cleaning. Do not expose them to ultrasonic cleaning.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code j
- Treatment state
- treated
- Only after these treatments
- fissure filling with oil, fissure filling with resin
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Indicolite, p.83; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Indicolite — care (chemicals): Treatments with dye, oil, resin, wax or plastic are not permanent; keep it away from all solvents (including dish-washing liquids), chemicals and heat.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code k
- Treatment state
- treated
- Only after these treatments
- fissure filling with oil, fissure filling with resin
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Indicolite, p.83; §6.2 k (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
WearIndicolite that has been treated by oiling or resin filling of fractures must not be cleaned ultrasonically, according to the CIBJO Blue Book. Treatments with dye, oil, resin, wax or plastic are not permanent, so Indicolite with oiled or resin-filled fractures should be kept away from all solvents (including dish-washing liquids), chemicals and high heat. CleaningThe GIA care and cleaning guide is given for the whole class and also applies to Indicolite; its item-by-item care advice is listed in full in the care part of the Tourmaline entry.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | care (cleaning) |
| Contact with acids, alkalis and household chemicals | Treatments with dye, oil, resin, wax or plastic are not permanent; keep it away from all solvents (including dish-washing liquids), chemicals and heat |
Treatments and identification leads
Registered treatmentsThe treatments registered for Indicolite are oiled fissures, heating and resin-filled fissures. Stability and frequencyOiled fissures: status treated, stability not stable, market prevalence occasional; heating: status treated, stability stable, market prevalence common; resin-filled fissures: status treated, stability not stable, market prevalence common. Values not givenThe identification leads and sources for each treatment are given as "—", meaning the cited source gives no value, not "none".
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| fissure filling with oilStatus: treated | occasionally | unstable | — | — | — |
| heatingStatus: treated | commonly | stable | Optimization | heating | — |
| fissure filling with resinStatus: treated | commonly | unstable | — | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Dyeing | — | — | Treatment | — | — |
| Irradiation | — | — | Treatment | — | — |
| Coating | — | — | Treatment | — | — |
Where each treatment acts (schematics): Filled / Fracture-filled · 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 Tourmaline); 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 Indicolite, the name register records "Blue Tourmaline" and "Indigolite", for which no restriction on use as a name is recorded (JJA/AGL Gemstone Nomenclature 2025 p.15); 2 further names in non-Latin scripts are listed in the name register below (2 with no restriction recorded on use as a name).
Standard and listing namesThe Chinese standard naming counterpart for Indicolite is tourmaline (GB/T 16552—2017 Table A.1), and this name is not listed in the original; the suggested listing name is blue tourmaline (Indicolite). Institution usageThe entry's own English name is Indicolite; the FTC text on file has no wording for this name (checked), and GIA, CIBJO and Gem-A wording is unchecked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe entry has its own Japanese name, and the wording of Japan's GSJ for it is not yet verified by this site. Trade and mineralogical namesThe mineralogical name means the blue tourmaline gem variety, and the trade name or synonym is Indigolite. Candidate search termsIn the name register, Indigolite and Blue Tourmaline are synonyms that may be matched automatically, while Japanese katakana transliterations for indigolite and blue tourmaline are kept only as candidate search terms. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Indicolite) and Japanese.
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 (4) | ||||
| Blue TourmalineEnglish | synonym | matched automatically | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
| IndigoliteEnglish | synonym | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| インディゴライトJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
| ブルー・トルマリンJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- インジゴライト／藍電気石 (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)
- 碧玺 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Blue tourmaline gem variety
- Trade names and synonyms
- Indigolite (synonym) · Blue Tourmaline (synonym)
Four-language names
- 简体中文
- 蓝碧玺
- 繁體中文
- 藍碧璽
- English
- Indicolite
- 日本語
- インジゴライト／藍電気石
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Tourmaline-supergroup 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 “Tourmaline” row of Table B.1: Heating Optimization; Filling Graded — see §5.4.1, Table 1; Dyeing Treatment; Irradiation Treatment; Coating Treatment. The full row, with the effect column, is on the Tourmaline 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 |
|---|---|---|---|---|
| Blue Tourmaline | Tourmaline | blue | an untreated tier is listed; heating (Heated / Heat-treated) | also called indicolite |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.15
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
The material facts for Indicolite that are marked with a class scope are written by the cited clauses for tourmaline (the whole mineral group), not measured on Indicolite separately. Per the tourmaline (whole mineral group) clauses, the structure of Indicolite is crystalline and trigonal, Mohs hardness is 7–8 and there is no cleavage; density is 2.46–3.26 g/cm³, which this site notes is derived from the clause value of 3.06 with a tolerance of +0.20/−0.60. Likewise per the tourmaline (whole mineral group) clauses, the optic character of Indicolite is anisotropic, uniaxial negative; the refractive index is 1.615–1.655, which this site notes is derived from the clause value of 1.624–1.644 with a tolerance of +0.011/−0.009; and birefringence is 0.018–0.04, where this site notes that the clause has further sub-grades, so the overall value is used. Pleochroism in the untreated state is moderate to strong, in lighter and darker shades of the body colour, and the lustre in the untreated state is vitreous. The UV-visible spectrum is registered as general absorption in the red region for blue and green tourmaline, with a strong absorption band at 498nm.
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”.
Luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for tourmaline (the whole mineral group), so they are not repeated on the Indicolite page; see the material facts on the Tourmaline entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Indicolite (how to read class-level values).
Structure
Indicolite — structure (overall): crystalline
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Indicolite — structure (crystal system): trigonal
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Indicolite — structure (crystal habit): rounded trigonal prisms or more complex ditrigonal prism-and-pyramid combinations; the crystal faces are distinctly striated lengthwise.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Indicolite — 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
- tourmaline (the whole mineral group)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Indicolite — cleavage: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
For Indicolite, the stability of fissure filling with oil is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with oil
- Qualification
This says how well the treatment holds up, not how durable Indicolite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Indicolite, 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 Indicolite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Indicolite, the stability of fissure filling with resin is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with resin
- Qualification
This says how well the treatment holds up, not how durable Indicolite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Physical properties
Indicolite — density: 2.46–3.26 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
- Qualification
The clause we cite gives 3.06, with a stated tolerance of +0.20 / -0.60. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Indicolite — optic character: uniaxial, optically negative (anisotropic)
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Indicolite — refractive index: 1.615–1.655
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
- Qualification
The clause we cite gives 1.624–1.644, with a stated tolerance of +0.011 / -0.009. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Indicolite — birefringence: 0.018–0.04
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Indicolite — pleochroism: moderate to strong, in lighter and deeper shades of the body colour.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Indicolite — spectrum (UV-visible): blue and green tourmaline: general absorption in the red region; 498 nm strong absorption band.
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): §5.1.10 UV-visible spectrum (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Indicolite — optical effect (chatoyancy): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Indicolite — optical effect (colour change): seen; rare
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
- CIBJO definitions
- chatoyancy, colour change
Quality factors
Indicolite — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- tourmaline (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.10 (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): 1.635 / 2.86; Closest values: 1Prehnite 1.625 / 2.88, 2Larimar 1.62 / 2.82, 3Datolite 1.646 / 2.95, 4Danburite 1.633 / 3, 5Sugilite 1.61 / 2.77
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, Indicolite is placed under “Tourmaline”; for identification, see the Tourmaline entry, and for the list of required tests, see the laboratory testing page. According to CIBJO's register, the conclusion on synthetics applies to any treatment state: no synthetic Indicolite is available on the market. Among Indicolite in trade, fissure filling with oil occurs occasionally, heating occurs commonly, and fissure filling with resin occurs commonly.
The CIBJO laboratory protocol covers Indicolite under “Tourmaline” (§6.1.86): see identification on the Tourmaline entry; the required tests are listed on the CIBJO laboratory protocol table for Tourmaline.
How far testing can go
Indicolite — 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 Indicolite in trade, the reported frequency of fissure filling with oil is “occasionally”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with oil
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Indicolite 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
For Indicolite in trade, the reported frequency of fissure filling with resin is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with resin
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
The clause-level definition for Indicolite is registered as a direct CIBJO definition under the entry Indigolite (Indicolite), defined as the violetish to greenish blue variety of tourmaline. 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 |
|---|---|---|---|
| Indigolite (Indicolite) | 7.2.1.114 | violetish to greenish blue variety of tourmaline | 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).
- eCFR (United States). 16 CFR § 23.24 — Disclosure of treatments to gemstones. In: 16 CFR Part 23 — Guides for the Jewelry, Precious Metals, and Pewter Industries.
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
Related-entry tree for Tourmaline on this site: 12 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Indicolite) is marked.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Tourmaline-supergroup minerals and gem varieties | Live |
| Treatments recorded for this material | Heated / Heat-treated, Filled / Fracture-filled (via parent material), Dyed (via parent material), Irradiated (via parent material), Coated (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Indicolite 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.