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
Verdelite
Also known asGreen Tourmaline · Verdelith
A gem variety name for green Tourmaline; the causes and tones of the green vary, and the colour and any treatment must be identified. Also known as Verdelith. 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 Verdelite 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 VerdeliteHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Verdelite4 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing VerdeliteCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of VerdeliteEach value with its source and check date
- Verdelite 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 VerdeliteThe listing name to use; what must be disclosed before sale
- Standard clauses that define VerdeliteWhich 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
Green tourmaline is a green colour variety of tourmaline (mostly elbaite, sometimes dravite–uvite mixtures). Its green is not of a single cause: trace iron (and possibly titanium) can give green, while traces of vanadium, chromium, or both in dravite–uvite mixtures can give rich greens rivaling tsavorite and even emerald—the material dealers call chrome tourmaline, though not all such stones are coloured by chromium. Chromium/vanadium green differs from iron green and must be distinguished. Green crystals likewise form in pockets of granite-bearing pegmatites.
Scope: Applies to explaining the colouration and occurrence of natural green tourmaline colour varieties, covering two distinct mechanisms: iron-caused green and chromium / vanadium-caused green; not applicable to synthetics or determining the locality of a specific sample.
Sources G&G Spring 2023 · GIA Tourmaline Description
Where it forms
Granite-bearing pegmatites (green elbaite); crystals occur in pegmatite pockets.
Sources G&G Spring 2023 · GIA Tourmaline Description
Green is not a common colour everywhere; in the Pala district, for instance, transparent faceting-grade green tourmaline is relatively uncommon.
Sources G&G Spring 2023 · GIA Tourmaline Description
How it forms, step by step
The pegmatite's residual fluid crystallises and tourmaline grows.
Sources G&G Spring 2023 · GIA Tourmaline Description
Iron (±Ti) entering the lattice can give green; if the host is dravite–uvite carrying traces of vanadium and/or chromium, more saturated green results.
Sources G&G Spring 2023 · GIA Tourmaline Description
Green can vary over growth to form colour zones within a crystal (as in watermelon tourmaline).
Sources G&G Spring 2023 · GIA Tourmaline Description
Link to appearance
A rich green appearance may come from vanadium/chromium or from iron; colour alone cannot fix the chromophore, and the trade name “chrome tourmaline” does not guarantee chromium colouring.
Sources GIA Tourmaline Description · G&G Spring 2007
Timescale
The cited sources give no absolute timescale for green tourmaline formation.
Sources G&G Spring 2023 · GIA Tourmaline Description
Related base materials
- Tourmaline group (mostly elbaite; some dravite–uvite): colour variety of tourmaline; verdelite
Supporting findings
Overall, green tourmaline forms in pockets of granite-bearing pegmatites, its green depending on which trace elements enter the lattice (iron, or vanadium/chromium); in some districts (e.g. Pala) green crystals are relatively uncommon yet facetable.
Evidence grade BScope: A multi-source synthesis of setting and colour cause; the scarcity note is a specific-district observation and not generalisable.
Sources G&G Spring 2023 · GIA Tourmaline Description
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- TanzaniaChrome tourmaline (colored mostly by vanadium).
Sources GIA Tourmaline Description
- 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
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
Opinion holds that minute amounts of iron — and perhaps titanium — give tourmaline its green and blue colours.
Evidence grade AScope: A general statement on tourmaline colouring; it does not cover chromium/vanadium green and gives no quantities.
Sources GIA Tourmaline Description
Dravite–uvite mixtures carrying traces of vanadium, chromium, or both produce rich greens (rivalling tsavorite and even emerald), sold as “chrome tourmaline” even though not always coloured by chromium; this mechanism differs from iron-derived green.
Evidence grade AScope: Concerns Cr/V green in dravite–uvite mixtures; it must not be extended to all green tourmaline, nor used to assert any specimen is chromium-coloured from its name.
Sources GIA Tourmaline Description
Spectroscopic and chemical analyses show that green trapiche tourmaline from Zambia is uvite, coloured green by a vanadium-related mechanism.
Evidence grade AScope: A mechanism for a single-locality (Zambia) sample; a locality-specific case not to be generalised to all green tourmaline.
Sources G&G Spring 2007
Other research findings
Green tourmaline is a colour variety of tourmaline, its green potentially arising in different host species (elbaite, or dravite–uvite mixtures); it is not an independent mineral species.
Evidence grade AScope: Establishes the colour-variety identity; it does not name the species of any given specimen.
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 green tourmaline formation.
- Cr/V-green data come mainly from individual localities (e.g. Zambian trapiche); the cited sources do not support a global generalisation.
- The cited sources give no quantitative share of iron-green versus chromium/vanadium-green in natural green tourmaline.
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
- Verdelite (green 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
Verdelite is Green tourmaline gem variety; use "Verdelite (green tourmaline)" for listings, and disclose any known treatments.
Evidence
What this means for you
Before buying, check the recommended listing name "Verdelite (green 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 Verdelite, is set out in full under care on the Tourmaline entry.
Care
Verdelite — 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
- filling, 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, Verdelite, p.81-82; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Verdelite — 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
- filling, 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, Verdelite, p.81-82; §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
CleaningCleaning Verdelite: the conclusion registered by The World Jewellery Confederation (CIBJO) is that treated Verdelite, and only where it has been filled, oil fracture-filled or resin fracture-filled, must not be cleaned ultrasonically. ChemicalsVerdelite and chemicals: likewise for treated stones that have been filled, oil fracture-filled or resin fracture-filled only, the effects of treatments such as dyeing, oiling, resin impregnation, waxing or plastic impregnation are not permanent, and Verdelite should be kept away from all solvents (detergents included), chemicals and heat. CleaningThe GIA care and cleaning guide is given for the whole class and so also applies to Verdelite; each care recommendation 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 recorded for Verdelite are heat treatment, resin fracture filling, filling and oil fracture filling, all with the status treated. Stability and frequencyHeat treatment has stability stable and prevalence common; resin fracture filling, filling and oil fracture filling all have stability not stable and prevalence rare. Values not givenThe identification leads and source for every treatment are shown 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 |
|---|---|---|---|---|---|
| heatingStatus: treated | commonly | stable | Optimization | heating | — |
| fissure filling with resinStatus: treated | rarely | unstable | — | — | — |
| fillingStatus: treated | rarely | unstable | Graded — see §5.4.1, Table 1 | — | — |
| fissure filling with oilStatus: treated | rarely | unstable | — | — | — |
| Dyeing | — | — | Treatment | — | — |
| Irradiation | — | — | Treatment | — | — |
| Coating | — | — | Treatment | — | — |
Where each treatment acts (schematics): Heated / Heat-treated · Filled / Fracture-filled
“—” 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 Verdelite, the name register records "Green Tourmaline" and "Verdelith", for which no restriction on use as a name is recorded (JJA/AGL Gemstone Nomenclature 2025 p.15; CIBJO Gemstone Book 2022 Annex 8 “verdelith”); 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 suggested listing name for Verdelite is green tourmaline (Verdelite). The corresponding national-standard name is tourmaline (GB/T 16552—2017 Table A.1), and the name itself is not listed in the original. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Verdelite) and Japanese; the mineralogical name means a green gem variety of tourmaline. Institution usageOn authority wording, CIBJO lists Verdelite (CIBJO Gemmological Laboratories Book 2024); the FTC text contains no wording for this name (checked); GIA and Gem-A are unchecked; bodies without a recorded wording show the entry's own English name for Verdelite, which does not represent their position. Japanese namesThe wording used by GSJ (Japan) is not yet verified by this site, and the entry has its own Japanese name. Candidate search termsSynonyms include Green Tourmaline (JJA/AGL gem names handbook 2025) and Verdelith (CIBJO Gemstone Book 2022 Annex 8), and the Japanese transliteration of "green tourmaline" is a search candidate only.
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) | ||||
| Green TourmalineEnglish | synonym | matched automatically | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
| VerdelithEnglish | synonym | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “verdelith” |
| グリーン・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
- ベルデライト／緑電気石 (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
- Green tourmaline gem variety
- Trade names and synonyms
- Verdelith (synonym) · Green Tourmaline (synonym)
Four-language names
- 简体中文
- 绿碧玺
- 繁體中文
- 綠碧璽
- English
- Verdelite
- 日本語
- ベルデライト／緑電気石
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 Table B.1Verdelite is classified under GB/T 16552—2017 Annex B Table B.1 by this site applying the tourmaline row: heat treatment is listed as an enhancement; filling is listed as graded, with the grade definitions on the treatments page; dyeing, irradiation and coating are listed as treatments. The full row, including the effect column, is in the tourmaline entry, and the notes to Table B.1 are on the treatments page. JJA/AGL designationsIn the main gemstone nomenclature table of the November 2025 revision of the Japanese JJA/AGL Definitions and Nomenclature of Gemstones and Ornamental Materials, Green Tourmaline has the species tourmaline and the colour green, with a no-treatment grade and heating (heat treatment) listed; how to read the JJA/AGL table is explained on the treatments page.
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 |
|---|---|---|---|---|
| Green Tourmaline | Tourmaline | green | an untreated tier is listed; heating (Heated / Heat-treated) |
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 composition (phase) of Verdelite is elbaite (tourmaline group); CIBJO registers its untreated body colour as yellowish green to bluish green, and in chapter 7 of the CIBJO book the colour descriptions for entries such as green sapphire, chrome tourmaline and euclase also mention green or a greenish tint. Most structural, durability and optical facts take values for tourmaline (the whole mineral group): crystalline, trigonal; Mohs hardness 7–8, cleavage none; density 2.46–3.26 g/cm³, derived from the clause value of 3.06 and tolerances of +0.20 and −0.60; optic character anisotropic, uniaxial, negative; refractive index 1.615–1.655, derived from the clause value of 1.624–1.644 and tolerances of +0.011 and −0.009; birefringence 0.018–0.04, which this site notes is the overall value although the clause has finer sub-ranges; untreated, pleochroism moderate to strong, in different depths of body colour, and untreated, the quality factor (lustre) vitreous.
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 Verdelite 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 Verdelite (how to read class-level values).
Definition
Verdelite — composition (phase): elbaite (tourmaline group)
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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 Verdelite, 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 Verdelite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Verdelite, 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 Verdelite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Verdelite, the stability of filling is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- filling
- Qualification
This says how well the treatment holds up, not how durable Verdelite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Verdelite, 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 Verdelite itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Physical properties
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — 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
Verdelite — body colour: Yellowish green to bluish green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Green Sapphire, Chrome Tourmaline, Euclase and other entries also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
- CIBJO definitions
- chatoyancy, colour change
Quality factors
Verdelite — 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
Under the CIBJO laboratory protocol, Verdelite is covered under Tourmaline: for the identification of Verdelite see the identification part of the Tourmaline entry, and the list of required tests is on the laboratory testing page. No synthetic counterpart of Verdelite is available on the market. For Verdelite in trade, heating occurs commonly, while fissure filling with resin, filling and fissure filling with oil occur rarely.
The CIBJO laboratory protocol covers Verdelite 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
Verdelite — 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 Verdelite 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 Verdelite in trade, the reported frequency of fissure filling with resin is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with resin
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Verdelite in trade, the reported frequency of filling is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- filling
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Verdelite in trade, the reported frequency of fissure filling with oil is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with oil
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
Verdelite has a direct definition in the CIBJO Gemmological Laboratories Book 2024 under the term Verdelite, defined as a yellowish-green to bluish-green variety of tourmaline; the cross-check result is that it is defined directly by CIBJO, and no identically named English entry was found in this edition of the GB/T annex.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Verdelite | 7.2.1.257 | Yellowish green to bluish green 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 (Verdelite) 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 Verdelite 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.