On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural organic and biogenic materials · Organic or biogenic material · Natural identity; treatment status unknown
Ivory
Also known asElephant Ivory · Mastodon Ivory (conditional name)
Dentine material taken from animal tusks or teeth; the species must be identified. Elephant material is listed in CITES Appendix I, with some African elephant populations in Appendix II. 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.
Questions people ask about Ivory
Every sentence below is followed by the registered fact it rests on; answers add no new facts and promise no outcome.
Q1Is it legal to trade elephant ivory?
Under the current CITES Appendices, Asian elephants and African elephants are listed in Appendix I, except the African elephant populations of Botswana, Namibia, South Africa and Zimbabwe, which are in Appendix II under annotation A11, which deems all other specimens to be Appendix I specimens.CITES Appendices (2026)A CITES listing covers parts and derivatives as well as the animal, which is how worked ivory comes within it, and trade in specimens of Appendix I species is to be authorised only in exceptional circumstances.CITES Appendices (2026) · CITES Convention textNaming, disclosure and labelling information on this site is reference material and does not constitute legal advice. Actual labelling duties follow the regulations in force in each jurisdiction and the testing certificates that accompany the goods; verify independently or consult a professional before relying on it.What this page can answer
Q2How can you tell real ivory from imitations?
Ivory looks much like mammoth ivory and imitation ivory, so they are hard to separate by sight, and identification calls for an accredited laboratory testing internal structure and composition.CIBJO Gemstone Book 2022No synthetic ivory is commercially available.CIBJO Gemstone Book 2022Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.What this page can answer
Q3What is ivory made of?
Ivory is animal dental tissue, not a mineral: it consists mainly of hydroxyapatite and collagen.G&G Summer 2023Its colour is recorded as white to pale yellow.GB/T 16553—2017
Q4How should ivory be cleaned and cared for?
Ultrasonic and steam cleaners should be avoided, as should solvents; a cloth dampened with methylated spirits is the recorded way to wipe it.Gems & Gemology 1987 (Martin)Heat makes it shrink and discolour, and chemicals attack it.Gems & Gemology 1987 (Martin)Prong and bezel settings call for caution, and flush, channel and pavé are best avoided.Gems & Gemology 1987 (Martin)
Q5Does ivory turn yellow?
Yes: it yellows with age, oils, lotions or perfume from handling may discolour it, and display-case heat, sunlight and artificial light call for caution.Gems & Gemology 1987 (Martin)
Q6Is ivory bleached or dyed?
Bleaching is used on ivory to lighten the colour or remove spots, and it is stable and hard to detect.GB/T 16553—2017In dyed ivory, the colour is uneven under magnification and concentrated between fissures, and acetone or absolute ethanol can wipe it off.GB/T 16553—2017AGTA marks bleached, dyed or paraffin-impregnated ivory as needing special care: no chemicals or ultrasonic cleaning, and it may discolour in time.AGTA Gemstone Information Manual, 17th ed.
What this page can answer
This page covers
- How Ivory forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify IvoryIdentification points from the research literature; how far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Ivory5 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing IvoryCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of IvoryEach value with its source and check date
- Ivory in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name, names in national standards; 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 IvoryHow people have used it, with museum objects
- Listing and disclosing IvoryThe listing name to use; what must be disclosed before sale
- Standard clauses that define IvoryWhich 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
Ivory is an animal-derived organic material: it comes from the tusks or teeth of animals and is biogenic dental tissue, not a mineral species. It is composed mainly of hydroxyapatite (Ca10(PO4)6(OH)2, including carbonate-bearing carbonate hydroxyapatite) and organic matter such as collagen (composition data are given from a mammoth-ivory source, which states it is similar to elephant ivory). NOTE: the species involved must be identified first: the African elephant (Loxodonta africana) is listed in CITES Appendix I/II (the Botswana, Namibia, South Africa and Zimbabwe populations in Appendix II), and trade in its products is strictly regulated or banned; legality of source depends on the species and the applicable permits.
Scope: Applies to an overview of the identity, composition and compliance boundaries of "ivory" as an organic material of animal origin; for species-derived materials the species must be determined before the material is discussed, and the legality of the source is judged against the CITES Appendices and permits.
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
Where it forms
Biogenic: formed by the growth of the animal's dental tissue (tusk/tooth), not a geological ore-forming setting.
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
How it forms, step by step
The animal's dental tissue grows to form the tusk/tooth.
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
Ivory consists mainly of hydroxyapatite (with carbonate hydroxyapatite) and organic matter such as collagen.
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
For a species-derived material the species must first be identified to establish its status.
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
Source legality is judged by species and permits (e.g. African elephant ivory is strictly CITES-regulated).
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
Link to appearance
Ivory can be carved and shows a fine texture and colour/pattern; NOTE: appearance alone cannot distinguish natural ivory from imitations, which requires testing, and cannot infer the species.
Sources CITES Checklist · G&G Summer 2023
Timescale
The sources give no absolute timescale for the material itself (it is a product of animal growth).
Sources GIA Museum: Ivory Carving · CITES Checklist · G&G Summer 2023
Recorded localities
This is an organic material; its localities are the harvest or culture areas (waters or species ranges) recorded by authoritative sources.
Africa
- African elephant range States, AfricaSource species African elephant; CITES regulates by range State and Appendix, no locality list
Sources CITES: Elephants · CITES Resolution Conf. 10.10
Asia
- Asian elephant range States, AsiaSource species Asian elephant; CITES lists no specific countries
Sources CITES: Elephants · CITES Resolution Conf. 10.10
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.
Human use and museum objects
A treaty that bans trade in elephant ivory came into force during the mid-1970s. GIA supports that ban, and through education — training gemology students and others, law enforcement officers among them — helps tell natural ivory apart from imitation materials.
Evidence grade AScope: Concerns the history of the trade ban and compliance stance; not geological formation.
Sources GIA Museum: Ivory Carving
Objects in The Met and the Cleveland Museum of Art show ivory carved as a valued material since antiquity: a Roman statuette (Met 17.190.67, 3rd-4th century), Byzantine ivories (Cleveland 1951.114, 1925.1293), a Tang pedestal (Cleveland 1968.70) and later Benin altar tusks (Cleveland 1968.284, c. 1820; Met 1991.17.106). All are historical/artistic holdings and concern no modern trade; ivory's species and its CITES appendix level are given in this record's existing content.
Evidence grade AScope: Applies to historical and artistic objects explicitly recorded as ivory / elephant ivory; modern trade is not covered, nor are objects without a material designation.
Sources The Met 17.190.67 · Cleveland Museum of Art 1968.70 · Cleveland Museum of Art 1951.114 +3
- The Metropolitan Museum of Art — Ivory statuette of a reclining woman (17.190.67)
- Cleveland Museum of Art — Pedestal (1968.70)
- Cleveland Museum of Art — Ivory Pyx (Box) (1951.114)
- Cleveland Museum of Art — Ivory Plaque with Enthroned Mother of God ("The Stroganoff Ivory") (1925.1293)
- Cleveland Museum of Art — Ancestral Altar Tusk (1968.284)
- The Metropolitan Museum of Art — Altar Tusk (1991.17.106)
The ivory objects in these collections are historical and artistic holdings dating from antiquity to the early 20th century; all are existing museum collections and none concerns modern trade. Among the earliest are a Roman ivory statuette of a reclining woman (Met 17.190.67, 3rd-4th century CE), a Tang-dynasty ivory pedestal (Cleveland 1968.70, mid-700s), a Byzantine ivory pyx (Cleveland 1951.114, 500s) and the celebrated "Stroganoff Ivory" panel of the enthroned Mother of God (Cleveland 1925.1293, 950-1025). From Europe there is a 15th-century rosary terminal bead recorded as elephant ivory (Met 14.25.1250). From Nigeria come an ancestral altar tusk (Cleveland 1968.284, c. 1820, recorded as Elephant ivory, Benin Kingdom) and an altar tusk (Met 1991.17.106, ca. 1921-1933). Note that ivory imitations also occur — e.g. Met 67.503.130, a 19th-century embossed paper imitating old ivory carving — excluded by its material field, so this account counts only objects explicitly recorded as ivory / elephant ivory. For ivory the species must first be identified; the species relevant here and its CITES appendix level are given in this record's existing content (the African elephant, Loxodonta africana, is listed in CITES Appendix I/II). The objects above are recorded solely as historical and artistic holdings; they concern no modern trade and do not support any modern lawful ivory trade.
Sources The Met 17.190.67 · Cleveland Museum of Art 1968.70 · Cleveland Museum of Art 1951.114 +4
- The Metropolitan Museum of Art — Ivory statuette of a reclining woman (17.190.67)
- Cleveland Museum of Art — Pedestal (1968.70)
- Cleveland Museum of Art — Ivory Pyx (Box) (1951.114)
- Cleveland Museum of Art — Ivory Plaque with Enthroned Mother of God ("The Stroganoff Ivory") (1925.1293)
- The Metropolitan Museum of Art — Rosary Terminal Bead with the Virgin and Child, Saint Barbara, and Saint Catherine (14.25.1250)
- Cleveland Museum of Art — Ancestral Altar Tusk (1968.284)
- The Metropolitan Museum of Art — Altar Tusk (1991.17.106)
Scope: A museum object evidences only the existence and date of that artefact itself; it does not establish widespread ancient use of the material, nor does it attest the origin, naturalness, or treatment of any modern specimen. The collection objects are historical/artistic holdings; they concern no modern trade and imply no modern lawful ivory trade.
Objects cited
- The Met 17.190.67Ivory
- Cleveland Museum of Art 1968.70ivory
- Cleveland Museum of Art 1951.114ivory
- Cleveland Museum of Art 1925.1293ivory
- The Met 14.25.1250Elephant ivory
- Cleveland Museum of Art 1968.284Elephant ivory
- The Met 1991.17.106Ivory
How it is identified
Ivory resembles mammoth ivory and imitation ivory in appearance, which makes them hard to separate by sight and raises species and regulatory questions. Identification calls for an accredited laboratory to test internal structure and composition with instruments; absent testing, trade guidance asks for prudent disclosure of uncertainty rather than an appearance-based verdict.
Evidence grade AScope: Ivory-type identification requires an accredited laboratory; where species and regulations are involved, uncertainty should be disclosed prudently.
Sources CIBJO Gemstone Book 2022
Other research findings
Ivory is an animal-derived organic material (dental tissue), not a mineral species; it consists mainly of hydroxyapatite (with carbonate hydroxyapatite) and collagen.
Evidence grade BScope: Composition data are from a mammoth-ivory source that states it is similar to elephant ivory; a material-level composition description.
Sources G&G Summer 2023
For ivory the species must be identified first: the African elephant (Loxodonta africana) is listed in CITES Appendix I/II (the Botswana, Namibia, South Africa and Zimbabwe populations in Appendix II); legality of source depends on the species and permits.
Evidence grade AScope: The species-first compliance boundary; appendix level and legality differ by species and must be verified per species.
Ivory can be carved for artwork; natural ivory and imitations must be distinguished by testing (including for law-enforcement purposes).
Evidence grade AScope: Describes use and identification need; not a single-item verdict.
Sources GIA Museum: Ivory Carving
In the current CITES Appendices, the elephant family (Elephantidae) is listed with Elephas maximus and Loxodonta spp. in Appendix I, except the populations of Loxodonta africana of Botswana, Namibia, South Africa and Zimbabwe, which are in Appendix II subject to annotation A11. Under that annotation, all specimens other than the listed exceptions are deemed to be specimens of Appendix I species and are regulated accordingly.
Evidence grade AScope: States the Appendix status as printed in the CITES Appendices valid from 5 March 2026; it does not cover national law, exemptions or permits for any particular item. Not legal advice.
Sources CITES Appendices (2026)
A CITES listing covers more than the live animal: when a species is in an Appendix, the whole animal, live or dead, and all its parts and derivatives fall under the same Appendix, which is how worked elephant ivory comes within the listing. Trade in specimens of Appendix I species is to be authorised only in exceptional circumstances.
Evidence grade AScope: States only what the cited official text says. It does not cover other jurisdictions, later changes or any particular item. Not legal advice.
Sources CITES Appendices (2026) · CITES Convention text
Limits of this research
- Research status: Only partial material-specific findings found; gaps are stated as gaps
- Ivory is a species-derived material; the cited sources give no unified mineralogical definition of "ivory" as a material name, so the species must be identified first.
- The composition data come from a source on mammoth ivory (which it describes as similar to elephant ivory) and serve here as a general overview of ivory composition; the composition is therefore inferred from mammoth ivory.
- CITES appendix level differs by species (here only the African elephant Loxodonta africana I/II is covered); no sources for other elephant or tooth-bearing species have been found.
- No dedicated source stating "ivory requires species identification" has been found; that boundary is supported by the species-specific CITES listings and the source statements.
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
- Ivory (only where lawful and the species documentation is complete)
GB/T 16552—2017 Table A.3 “Ivory” · CIBJO Gemmological Laboratories Book 2024 §7.2.2.6 “Ivory”
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Bleached, Impregnated, Filled / Fracture-filled, Dyed
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
Ivory is often subjected to bleaching and impregnation. Under GB/T 16552-2017, bleaching counts as an optimization, so the plain gem name may be used (§5.4.2.1 a); impregnation is graded by the material used, and must be stated in the name wherever it counts as a treatment (§5.4.1, Table 1). Do not assume it is unenhanced.
Evidence
- GB/T · Table A.3, row 象牙 (Ivory)
What this means for you
Before buying, check the recommended listing name "Ivory (only where lawful and the species documentation is complete)" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- This entry's exact material identity is not fully settled.
- See “Disclosure and cautions” above
- Disclosure rules for the treatments above can change as authorities update their standards; re-check before relying on this page.
- Last reviewed
- 2026-09-01
Trade-name ruling
- Laboratory identification required before the name is used.
- Suggested listing name
- Ivory (only where lawful and the species documentation is complete)
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.
Care
Ivory — care (cleaning): ultrasonic and steamer: avoid; note: avoid solvents; wipe with a cloth dampened in methylated spirits.
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, Ivory row, CLEANING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ivory — care (light): may fade or revert to its original colour in strong light; do not wear or leave it in strong light for extended periods.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code f
- Treatment state
- treated
- Only after these treatments
- dyeing, surface waxing
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ivory, p.57-58; §6.2 f (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ivory — 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
- dyeing, impregnation, surface waxing
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ivory, p.57-58; §6.2 k (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ivory — care (special care): bleached, dyed for artistic effect or impregnated with colourless paraffin: special care (SC); avoid chemicals and ultrasonic cleaning; may discolour in time.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- bleaching, dyeing, surface waxing
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.X–XI, Gemstone Information Chart, Ivory & Bone B / D / W, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ivory — care (setting): prong and bezel: use caution; flush, channel and pavé: avoid.
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, Ivory row, SETTING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ivory — care (repair): jeweller's torch, pickle pot, polishing and thermal shock: avoid; note: heat makes it shrink and discolour, and chemicals attack it.
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, Ivory row, REPAIR column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ivory — care (display): heat in the display case, sunlight and artificial light: use caution; note: it yellows with age, and oils, lotions or perfume from handling may discolour it.
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, Ivory 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
LightCare for Ivory: for untreated Ivory, Martin's Gemstone Durability: Design to Display states that ultrasonic and steam cleaning should be avoided and solvents kept away, it may be wiped with a cloth dampened with industrial (methylated) spirit, torches, pickling after soldering, polishing and thermal shock should be avoided, heat makes it shrink and discolour, chemicals attack it, heat, daylight and artificial light in display cases call for caution, skin oils, lotions, perfume and the like may discolour it when handled, prong and bezel settings call for caution, and tension, channel and pavé settings should be avoided. ChemicalsFor dyed, impregnated or surface-waxed Ivory, CIBJO states it should be kept away from all solvents (including detergents of every kind), chemicals and heat. Special careFor bleached, dyed or surface-waxed Ivory, the AGTA Gemstone Information Manual states that special care is needed (marked SC), avoiding chemicals and ultrasonic cleaning, and that it may discolour over time. LightFor dyed or surface-waxed Ivory, CIBJO states that it fades or reverts to its original colour in strong light and should not be worn or left in strong light for long periods.
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| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | ultrasonic and steamer: avoid; note: avoid solvents; wipe with a cloth dampened in methylated spirits |
| Heat and thermal shock | jeweller's torch, pickle pot, polishing and thermal shock: avoid; note: heat makes it shrink and discolour, and chemicals attack it |
| Light and display | may fade or revert to its original colour in strong light; do not wear or leave it in strong light for extended periods; heat in the display case, sunlight and artificial light: use caution; note: it yellows with age, and oils, lotions or perfume from handling may discolour it |
| 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 |
| Wearing limits (knocks, settings) | prong and bezel: use caution; flush, channel and pavé: avoid |
Care entries by treatment state
The same entries grouped by the treatment state each applies to; each links to its full wording and source. Letters are CIBJO special-care codes, explained on the gemstone care page.
untreated
- ultrasonic and steamer: avoid; note: avoid solvents; wipe with a cloth dampened in methylated spirits
- prong and bezel: use caution; flush, channel and pavé: avoid
- jeweller's torch, pickle pot, polishing and thermal shock: avoid; note: heat makes it shrink and discolour, and chemicals attack it
- heat in the display case, sunlight and artificial light: use caution; note: it yellows with age, and oils, lotions or perfume from handling may discolour it
treated (Only after these treatments: dyeing, surface waxing)
treated (Only after these treatments: dyeing, impregnation, surface waxing)
treated (Only after these treatments: bleaching, dyeing, surface waxing)
Treatments and identification leads
Registered treatmentsThe treatments recorded for Ivory are impregnation, bleaching, dyeing, surface waxing and filling, all with the status treated. Values not givenImpregnation: stability not stable, prevalence common; bleaching: stable, common; dyeing: not stable, occasional; surface waxing: not stable, occasional; for filling, the cited source gives no value for stability or prevalence, which is not the same as “none”. Identification cluesAs identification leads, bleaching is used to lighten colour or remove spots and is stable and hard to detect; dyed material shows uneven colour under magnification, dyes may fluoresce distinctively under long-wave and short-wave UV, and the colour comes off when wiped with solvents such as acetone or anhydrous ethanol; filled areas differ in lustre from the ivory itself and contain gas bubbles, their fluorescence under long-wave and short-wave UV is mostly inconsistent with the host, and the infrared spectrum can detect the characteristic absorption bands of the filler.
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| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| impregnationStatus: treated | commonly | unstable | — | — | — |
| bleachingStatus: treated | commonly | stable | Optimization | — | See identification leads |
| dyeingStatus: treated | occasionally | unstable | Treatment | — | See identification leads |
| surface waxingStatus: treated | occasionally | unstable | — | — | — |
| fillingStatus: treated | — | — | Graded — see §5.4.1, Table 1 | — | See identification leads |
Where each treatment acts (schematics): Impregnated · Bleached · Dyed · Waxed · Filled / Fracture-filled
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022 · 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
Besides Ivory, the name register records "Elephant Ivory" and "Mastodon Ivory", for which no restriction on use as a name is recorded (CIBJO Gemstone Book 2022 Annex 8 “Elephant Ivory”; CIBJO Gemstone Book 2022 Annex 8 “Mastodon Ivory”).
Chinese standard nameThe Chinese formal name for Ivory comes from GB/T 16552—2017 Table A.3; the GSJ (Japan) formal name is the Japanese term for ivory, in both katakana and kanji forms. Names in four languagesFor the four-language names, the Simplified and Traditional Chinese names are the same, the English name is Ivory, and the Japanese name uses the same two forms. Recommended listing nameThe suggested listing name is ivory (only where legal and with complete species documentation). Institution usageAmong authority wordings, CIBJO lists Ivory, from 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, which does not represent their position. Candidate search termsIn the name register, Elephant Ivory may be matched automatically, while Mastodon Ivory is a search candidate only, based on the corresponding row of CIBJO Gemstone Book 2022 Annex 8. National standard namesFor national and regional formal names, Germany (RAL) uses Elfenbein, noting that it is subject to the strictest CITES EU controls; the European Union uses Ivory, noting that EU CITES imposes a de facto ban on commercial trade.
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.
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| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (2) | ||||
| Elephant IvoryEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Elephant Ivory” |
| Mastodon IvoryEnglish | narrower name (variety or subtype) | search candidate only | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Mastodon Ivory” |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- アイボリー／象牙
- Chinese formal name
- 象牙 (GB/T 16552—2017 Table A.3)
- Mineralogical name
- Ivory from animal tusk or tooth; species must be identified
- Trade names and synonyms
- Elephant Ivory (narrower name (variety or subtype)) · Mastodon Ivory (narrower name (variety or subtype); conditional name)
Four-language names
- 简体中文
- 象牙
- 繁體中文
- 象牙
- English
- Ivory
- 日本語
- 象牙／アイボリー
National and regional formal names
- Germany (RAL)
- Elfenbein (CITES EU strengstens geregelt)
- European Union
- Ivory (EU CITES: de facto ban on commercial trade)
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural organic and biogenic materials
- Browsing family
- Other animal-derived materials
- Identity tier
- Organic or biogenic material
- Mineral chemical class
- Not applicable
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
The ivory row of GB/T 16552—2017 Annex B Table B.1 lists for Ivory: bleaching, whose effect is to improve appearance, classed as an enhancement; filling, whose effect is to improve or change durability and appearance, with its category determined by the grade definitions of GB/T 16552—2017; and dyeing, whose effect is to change colour, classed as a treatment. The notes to Table B.1 and the definitions of each grade are on this site's treatments page.
GB/T 16552-2017, Annex B, Table B.1
Table B.1, row “Ivory” (p.18):
This table scrolls sideways on narrow screens.
| Method | Effect | Category |
|---|---|---|
| Bleaching | Improves appearance | Optimization |
| Filling | Improves or changes durability and appearance | Graded — see §5.4.1, Table 1 |
| Dyeing | Changes colour | Treatment |
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
The composition of Ivory is mainly hydroxyapatite and collagen; the inorganic part is a cryptocrystalline aggregate and the organic part amorphous. Mohs hardness 2–3, cleavage none, density 1.7–2 g/cm³. Optic character aggregate, birefringence not measurable for an aggregate. Refractive index 1.53–1.54, a reading often obtained by the spot method, a common value rather than an absolute limit. Untreated Ivory has pleochroism not measurable for an aggregate, weak to strong bluish-white or violet-blue luminescence, and a greasy to waxy lustre, and it softens in nitric or phosphoric acid. The UV-visible spectrum is not diagnostic; in the infrared spectrum, vibrations of phosphate ions and of functional groups in organic matter such as protein give characteristic bands in the mid-infrared region.
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
Ivory — composition (chemistry): chiefly hydroxyapatite plus collagen
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Structure
Ivory — structure (overall): The inorganic component is a cryptocrystalline aggregate, the organic component amorphous.
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Ivory — Mohs hardness: 2–3
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
Source & check 2026-09-20
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Ivory — cleavage: none
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
stability2 sources compared
Ivory — stability: Nitric and phosphoric acids soften it
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ivory — stability: low hardness, so it scratches easily; porous, so keep it away from coloured liquids; dissolves on contact with solvents such as nail varnish remover, so keep it away from all solvents and other strong chemicals; no ultrasonic cleaning; pieces with superficial colour or surface layers are not suitable for re-cutting or re-polishing.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code a, special-care code c, special-care code i, special-care code j, special-care code m
- Treatment state
- untreated
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ivory, p.57; §6.2 a, c, i, j, m (locator checked 2026-09-21)
- Fact checked on
- 2026-09-25
For Ivory, the stability of impregnation is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Ivory, the stability of bleaching is “stable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- bleaching
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Ivory, the stability of dyeing is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- dyeing
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Ivory, the stability of surface waxing is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- surface waxing
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
Physical properties
Ivory — density: 1.7–2 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Ivory — optic character: aggregate
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — refractive index: 1.53–1.54
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives this as a value commonly read by the spot (distant-vision) method. It is a common value, not an absolute limit.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — birefringence: not measurable on an aggregate
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — pleochroism: not measurable on an aggregate
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — fluorescence (overall): weak to strong, blue-white, violet-blue
GB/T 16553—2017
UV fluorescenceblue-whiteviolet-blueweak–strongDots 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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — spectrum (UV-visible): non-characteristic
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — spectrum (infrared): Diagnostic mid-IR bands come from the phosphate ion and from vibrating functional groups (radicals) in protein and other organic matter.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-22
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Ivory — magnification: wavy texture, engin-like texture
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): §5.3.7 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — body colour: white to pale yellow and light yellow
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 Calcite, Prehnite, Dolomite and other variety clauses also name white or a whitish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Quality factors
Ivory — quality factor (lustre): greasy to waxy
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): §5.3.7 (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): 1.535 / 1.85; Closest values: 1Mammoth Ivory 1.53 / 1.75, 2Black Coral 1.565 / 1.71, 3Coral 1.57 / 2, 4Chrysocolla 1.516 / 2.2, 5Synthetic Opal 1.45 / 2.08
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
Identification leads for dyed Ivory: under magnification the colour is unevenly distributed, mostly concentrated between fractures or at growth defects; under long-wave and short-wave UV the dye may show distinctive fluorescence; wiping with solvents such as acetone or anhydrous ethanol removes colour. In filled Ivory, fractures are usually filled with ivory powder mixed with resin, or with resin alone; under magnification the filled parts have a lustre different from the ivory itself and show gas bubbles; under long-wave and short-wave UV the fluorescence of filled parts mostly does not match the host; infrared spectra can detect characteristic absorption bands of the filler. In bleached Ivory, bleaching is used to lighten the colour or remove spots; the effect is stable and difficult to detect. GB/T 16553—2017, on which the dyeing, filling and bleaching leads are based, can be followed only as a reference for Ivory and does not directly govern it. The CIBJO laboratory protocol requires particular checks for dyeing, imitations and CITES control; its notes state that the microscope is used to observe growth structure, and that X-ray CT scanning is used in some cases to observe growth structure. No synthetic counterpart of Ivory is available on the market.
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: §6.2.6.
How far testing can go
Ivory that has undergone dyeing can be identified by the following features: Under magnification the colour is unevenly distributed and mostly concentrated between fissures or at growth defects; under UV light, long-wave or short-wave, the dye may show a distinctive fluorescence; wiping with acetone or absolute ethanol can remove the colour.
GB/T 16553—2017
- Treatment state
- colour treated
- Does this standard apply
- can be followed as a reference only
- Treatment
- dyeing
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (dyeing) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory that has undergone filling can be identified by the following features: Fissures are commonly filled with ivory powder mixed with resin, or with resin alone; under magnification the surface luster of the filled part differs from the host material and gas bubbles show in the filled area; under long- and short-wave UV the filled part mostly fluoresces differently from the host; infrared spectra show characteristic absorption bands of the filler.
GB/T 16553—2017
- Treatment state
- treated
- Does this standard apply
- can be followed as a reference only
- Treatment
- filling
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (filling) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory that has undergone bleaching can be identified by the following features: lightens the colour or removes spots. It is stable and not easy to detect.
GB/T 16553—2017
- Treatment state
- colour treated
- Does this standard apply
- can be followed as a reference only
- Treatment
- bleaching
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.7 (bleaching) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Ivory — 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 Ivory in trade, the reported frequency of impregnation is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Ivory in trade, the reported frequency of bleaching is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- bleaching
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Ivory in trade, the reported frequency of dyeing is “occasionally”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- dyeing
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Ivory in trade, the reported frequency of surface waxing is “occasionally”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- surface waxing
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
Ivory — what the CIBJO laboratory protocol says to watch for: dye, imitations, CITES issues
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Ivory — notes on test methods in the CIBJO laboratory protocol:
| Test method | What the protocol notes for it |
|---|---|
| Microscope: | Growth structures; |
| X-Ray CT scan: | In some cases to view growth structures |
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
Ivory has a clause-level definition in the CIBJO Gemmological Laboratories Book 2024 under the term Ivory; 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.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Ivory | 7.2.2.6 | Ivory consists of calcium phosphate (hydroxylapatite) with collagenous proteins. Most ivory is from elephant tusks although mammoth, walrus, hippopotamus, narwhal tusks and tusks of other animals are also used as ivory. Distinction criteria | Defined directly by CIBJO; also present in the GB/T annex. |
Evidence and sources
Authority basis and clause sources
Sources
- CIBJO – The World Jewellery Confederation. Gemmological Laboratories Book (Blue Book), Gemmological Commission 2024-1.
- CIBJO – The World Jewellery Confederation. The Gemstone Book (Blue Book), 2022.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- CITES Secretariat. Appendices I, II and III, valid from 5 March 2026.
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Other animal-derived materials | Live |
| Treatments recorded for this material | Bleached, Impregnated, Filled / Fracture-filled, Dyed | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Ivory 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.