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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
Hawksbill Turtle Shell
Also known asTortoise shell (not to be used as a name)
Shell material from the hawksbill turtle (Eretmochelys imbricata), grouped under "Turtle Shell" in GB/T; its sea turtle family is listed in CITES Appendix I. 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 Hawksbill Turtle Shell forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify Hawksbill Turtle ShellIdentification points from the research literature; how far lab testing can go
- Caring for and wearing Hawksbill Turtle ShellCleaning, heat, chemicals and light, as the cited sources give them
- Hardness of Hawksbill Turtle ShellEach value with its source and check date
- Hawksbill Turtle Shell 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: Has any of GIA, FTC, CIBJO or Gem-A put a name for it on record here?
- Name origin and history of Hawksbill Turtle ShellHow people have used it, with museum objects
- Listing and disclosing Hawksbill Turtle ShellThe listing name to use; what must be disclosed before sale
- Standard clauses that define Hawksbill Turtle ShellWhich 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
Tortoiseshell, in the traditional sense, is made from the shell scutes of the hawksbill turtle (Eretmochelys imbricata), a critically endangered species. Scutes of marine turtles are keratinous structures that grow from the animal's integument; beta-keratin protein makes up the mass of each, with calcium phosphate and calcium sulfate dispersed through the protein as a mineral component. Tortoiseshell is therefore a keratinous material grown by an animal, not a mineral. Every marine turtle appears in CITES Appendix I, and international trade in their products is banned; this record discusses the material purely for purposes of identification and genesis and passes no judgement on the legality of any source.
Scope: Applies to the biogenic origin, composition and trade-control background of hawksbill turtle shell material; does not cover determination of the legality of sources and does not provide purchasing advice.
Sources CITES Checklist · Journal article (tortoiseshell ATR-IR)
Where it forms
The integument of the marine turtle — scutes grow from the animal's skin over the carapace.
Sources Journal article (tortoiseshell ATR-IR)
Tortoiseshell objects also circulate through museum, private and antique trade as a processed organic material.
Sources Journal article (tortoiseshell ATR-IR)
How it forms, step by step
As the turtle grows, keratinous scutes form in the animal's skin, providing the raw tortoiseshell material.
Sources Journal article (tortoiseshell ATR-IR)
Each scute consists of beta-keratin protein with dispersed mineral phases (calcium phosphate and calcium sulfate).
Sources Journal article (tortoiseshell ATR-IR)
The raw scutes are boiled, their mineral content is driven off, and the flexible beta-keratin left behind is shaped into the intended item.
Sources Journal article (tortoiseshell ATR-IR)
Substitute materials (bovid horn, casein plastic, cellulose nitrate, cellulose acetate, polyester) are also worked into visually similar faux tortoiseshell.
Sources Journal article (tortoiseshell ATR-IR)
Link to appearance
The characteristic mottled brown-amber appearance comes from the translucent beta-keratin matrix; horn, casein and plastic products share similar spectra and are hard to distinguish visually.
Sources CITES Checklist · Journal article (tortoiseshell ATR-IR)
Timescale
No authoritative growth-rate figure for hawksbill scutes was available to this record, so no timescale is stated.
Sources Journal article (tortoiseshell ATR-IR)
Supporting findings
Tortoiseshell is of biological origin: the scutes grow and are secreted by the turtle's integument, in the reef-ocean ecosystem the animal inhabits.
Evidence grade AScope: States the biological origin only; no geography or farming information.
Sources Journal article (tortoiseshell ATR-IR)
Recorded localities
This is an organic material; its localities are the harvest or culture areas (waters or species ranges) recorded by authoritative sources.
Seas and coasts
- Worldwide (hawksbill turtle range)CITES Appendix I species; trade prohibited
Sources CITES: Hawksbill turtle · Mindat
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
The collection evidence shows datable tortoiseshell objects concentrated in 17th-20th-century decorative work (e.g. Met 91.1.2153a–c inrō; Cleveland 1949.539.a marquetry cabinet; Met 2000.559a, b locket and chain); Pacific turtle-shell ornaments date to the late 19th-early 20th century (Met 1979.206.1473, 1999.47.62). Ceramics or photographs named "tortoiseshell" are excluded, and horn, casein or plastic imitations may occur among such holdings, a title field being insufficient to confirm the material. The source species is CITES Appendix I and trade is banned.
Evidence grade AScope: Applies to objects recorded as tortoiseshell; horn, casein or plastic imitations may occur among them. Cultural attribution follows museum records and is not extended by inference.
Sources The Met 91.1.2153a–c · The Met C.I.X.50.1.3 · The Met 2000.559a, b +3
- The Metropolitan Museum of Art — Tortoiseshell and Basketry Inrō (91.1.2153a–c)
- The Metropolitan Museum of Art — Stick of tortoiseshell (C.I.X.50.1.3)
- The Metropolitan Museum of Art — Locket and Chain (2000.559a, b)
- Cleveland Museum of Art — Cabinet (1949.539.a)
- The Metropolitan Museum of Art — Kapkap (pendant or head ornament) (1979.206.1473)
- The Metropolitan Museum of Art — Dala (Pendant or Head Ornament) (1999.47.62)
Objects recorded as tortoiseshell in these collections span the 17th-20th centuries and are mostly decorative: a 17th-century Japanese inrō built on tortoiseshell under a lacquered rattan "net" (Met 91.1.2153a–c) and a stick of tortoiseshell of 1700-1950 (acc. C.I.X.50.1.3); in Europe, a French ebony cabinet of about 1690 marquetried in metal and tortoiseshell (Cleveland 1949.539.a) and a tortoiseshell locket and chain of about 1870 (Met 2000.559a, b). From the Pacific come ornaments of turtle shell with Tridacna shell (Met 1979.206.1473, 1999.47.62). Note that several objects whose titles contain "tortoiseshell" are in fact ceramics with a "tortoiseshell" glaze or pattern (e.g. Jizhou ware teabowls) or a photograph, and not tortoiseshell material; these are excluded. Tortoiseshell is taken from the scutes of the CITES Appendix I hawksbill turtle (Eretmochelys imbricata), whose products are banned from international trade; because the raw scute resembles horn, casein and plastics used as imitations, imitation pieces may also occur among such holdings, and a title field alone does not confirm the material. This record serves historical identification and genesis only, concerns no modern trade, and implies no modern lawful trade.
Sources The Met 91.1.2153a–c · The Met C.I.X.50.1.3 · The Met 2000.559a, b +3
- The Metropolitan Museum of Art — Tortoiseshell and Basketry Inrō (91.1.2153a–c)
- The Metropolitan Museum of Art — Stick of tortoiseshell (C.I.X.50.1.3)
- The Metropolitan Museum of Art — Locket and Chain (2000.559a, b)
- Cleveland Museum of Art — Cabinet (1949.539.a)
- The Metropolitan Museum of Art — Kapkap (pendant or head ornament) (1979.206.1473)
- The Metropolitan Museum of Art — Dala (Pendant or Head Ornament) (1999.47.62)
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 source species is CITES Appendix I; the collection objects are historical holdings that concern no modern trade and imply no modern lawful trade, and imitations may occur among them. Cultural attribution follows museum records and is not extended by inference.
Objects cited
- The Met 91.1.2153a–cInrō: single case; tortoiseshell under rattan “net” covered with lacquer (urushi); ojime: flower petals, brushwood; patinated copper with mixed-metal inlays; netsuke: turtle; carved wood
- The Met C.I.X.50.1.3Tortoiseshell
- The Met 2000.559a, bTortoiseshell
- Cleveland Museum of Art 1949.539.aebony, marquetry in metal and tortoiseshell
- The Met 1979.206.1473Tridacna shell, turtle shell, fiber
- The Met 1999.47.62Tridacna shell, turtle shell, fiber, glass bead
How it is identified
Hawksbill-type tortoiseshell can look like imitations or other keratinous material, and appearance cannot settle its identity. Identification must be performed by an accredited laboratory that tests structure and composition with instruments; where protected species are involved, particular care is due, and trade guidance asks that uncertainty be disclosed rather than judged from looks.
Evidence grade AScope: Tortoiseshell identification requires an accredited laboratory, with particular care where protected species are involved.
Sources CIBJO Gemstone Book 2022
Other research findings
Tortoiseshell is traditionally produced from the scutes of the critically endangered hawksbill turtle (Eretmochelys imbricata); all marine turtles are listed in CITES Appendix I, and trade in their products is prohibited internationally.
Evidence grade AScope: Defines the source species and trade-control level; no judgement on source legality and no sourcing advice.
Sources Journal article (tortoiseshell ATR-IR) · CITES Checklist
beta-keratin protein forms the bulk of marine turtle scutes, with calcium phosphate and calcium sulfate dispersed through it as a mineral component; tortoiseshell is accordingly a keratinous material grown by an animal.
Evidence grade AScope: Applies to the composition of raw scutes, not to applied colourants on finished objects.
Sources Journal article (tortoiseshell ATR-IR)
To make tortoiseshell the raw scutes are boiled and their mineral content removed, leaving flexible beta-keratin to be formed; horn, casein and several plastics are also used to simulate it, and infrared spectroscopy is used to discriminate the source.
Evidence grade AScope: Describes processing of natural scutes and common simulants; does not imply all objects are treated.
Sources Journal article (tortoiseshell ATR-IR)
Marine-turtle tortoiseshell can be identified by its beta-keratin ATR-FTIR signature; hawksbill and green turtle cannot be distinguished from the infrared spectra alone.
Evidence grade AScope: Limited to infrared identification; species confirmation still requires other methods such as DNA analysis.
Sources Journal article (tortoiseshell ATR-IR)
Tortoiseshell comes from the shell plates of marine turtles, predominantly the hawksbill. The CITES Appendices list the whole sea-turtle family (Cheloniidae spp.) in Appendix I, so the hawksbill is covered by that family listing rather than by a separate line of its own.
Evidence grade AScope: States the Appendix status as printed in the Appendices valid from 5 March 2026; it does not cover national law or permits for any particular item.
Sources CITES Appendices (2026) · Journal article (tortoiseshell ATR-IR)
Under the CITES Convention, trade in specimens of Appendix I species is subject to particularly strict regulation and is to be authorised only in exceptional circumstances; among the conditions for an import permit, the importing State's Management Authority must be satisfied that the specimen is not to be used for primarily commercial purposes.
Evidence grade AScope: Summarises the Convention text only. CITES governs international trade; each Party may adopt stricter domestic measures, and exemptions such as those in Article VII are not covered here. Not legal advice for any particular item.
Sources CITES Convention text
A CITES listing covers more than the live animal: when a species is in Appendix I, the whole animal, live or dead, and all its parts and derivatives fall under the same Appendix, which is how worked tortoiseshell comes within the listing. In the Convention, 'trade' means export, re-export, import and introduction from the sea.
Evidence grade AScope: Summarises the Convention text only. CITES governs international trade; each Party may adopt stricter domestic measures, and exemptions such as those in Article VII are not covered here. Not legal advice for any particular item.
Sources CITES Appendices (2026) · CITES Convention text
The CITES Appendices valid from 5 March 2026 list the whole sea-turtle family (Cheloniidae spp.) in Appendix I; the hawksbill turtle is covered by this family listing rather than by an entry under its own name. A listing covers the whole animal, live or dead, and its parts and derivatives fall in the same Appendix.
Evidence grade AScope: States only what is printed in the CITES Appendices valid from 5 March 2026 and their interpretation notes; shell from other turtle families depends on their own listings, and national law, exemptions and permits are not covered. Not legal advice.
Sources CITES Appendices (2026)
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The source species is CITES Appendix I; trade is illegal. This record is for identification and genesis only.
- This record relies mainly on one peer-reviewed identification paper and the CITES database; processing and dating are not fully covered.
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
- Hawksbill turtle shell: not recommended for commercial listing
GB/T 16552—2017 Table A.3 “Tortoise Shell”, 5.2.1 a), 5.2.1 d) · CIBJO Gemmological Laboratories Book 2024 §7.2.2.11
Construction or treatment status
Natural identity; treatment status unknown
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
"Hawksbill Turtle Shell" is a market name rather than a mineral species name; before using it, verify: Laboratory identification required before the name is used.
Evidence
- GB/T · Table A.3, row 龟甲 (Turtle Shell)
What this means for you
Before buying, check the recommended listing name "Hawksbill turtle shell: not recommended for commercial listing" 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
- Last reviewed
- 2026-09-01
Trade-name ruling
- Laboratory identification required before the name is used.
- Suggested listing name
- Hawksbill turtle shell: not recommended for commercial listing
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
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
VerifyNames, standards, technical facts, clauses and sources
Names
For Hawksbill Turtle Shell, "Tortoise shell" must not be used as a name (GB/T 16552—2017 Table A.3 “Tortoise Shell”; CIBJO Gemmological Laboratories Book 2024 §7.2.2.11; CITES Appendices 2026 CHELONIIDAE; CITES Convention text Article I(b)(ii)).
Chinese standard nameThe Chinese standard name for Hawksbill Turtle Shell comes from GB/T 16552—2017 Table A.3, and the GSJ (Japan) has its own formal Japanese name. Names in four languagesNames are registered in four languages: Simplified Chinese, Traditional Chinese, English (Hawksbill Turtle Shell) and Japanese; the mineralogical name refers to the shell material of the hawksbill sea turtle (Eretmochelys imbricata). Candidate search termsThe trade name or synonym Tortoise shell is a broader trade name covering all turtle shell, used only as a candidate search term and not as a name; related high-risk names include coral and giant clam. The tortoiseshell row of GB/T 16552 Table A.3 gives no separate English name for Hawksbill Turtle Shell, so using Tortoise shell to mean hawksbill specifically is an over-narrow restriction without backing from the standard. National standard namesAmong national and regional standard names, Germany (RAL) uses Schildpatt (CITES EU Annex A), and the EU uses Tortoiseshell, with EU CITES Annex A noting that commercial trade is prohibited. Institution usageOn authority wording, the FTC and CIBJO texts on file contain no wording for Hawksbill Turtle Shell (checked), and GIA and Gem-A are unchecked; bodies without a recorded wording show the English name of Hawksbill Turtle Shell itself, which does not represent their position. Sub-names and unacceptable namesThe suggested listing name is Hawksbill Turtle Shell, with commercial listing not recommended.
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 |
|---|---|---|---|---|
| not to be used as a name (1) | ||||
| Tortoise shellEnglish | market name | search candidate only | not to be used as a name | GB/T 16552—2017 Table A.3 “Tortoise Shell”; CIBJO Gemmological Laboratories Book 2024 §7.2.2.11; CITES Appendices 2026 CHELONIIDAE; CITES Convention text Article I(b)(ii); Note: Related high-risk name “Coral, giant clam shell”. |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- タイマイ／玳瑁
- Chinese formal name
- 玳瑁 (GB/T 16552—2017 Table A.3)
- Mineralogical name
- Shell material from hawksbill turtle (Eretmochelys imbricata)
- Trade names and synonyms
- Not to be used as a name: Tortoise shell (market name)
Four-language names
- 简体中文
- 玳瑁
- 繁體中文
- 玳瑁
- English
- Hawksbill Turtle Shell
- 日本語
- 玳瑁／タイマイ甲
National and regional formal names
- Germany (RAL)
- Schildpatt (CITES EU Anhang A)
- European Union
- Tortoiseshell (EU CITES Annex A: commercial trade prohibited)
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
What it is and how it's identified
The Mohs hardness of Hawksbill Turtle Shell is 2–3; the cited GB/T 16553—2017 clause is written for turtle shell and states that the shell of the hawksbill turtle is commonly called by this name. The CIBJO Gemstone Book 2022 registers untreated Hawksbill Turtle Shell as soft, easily scratched and porous, to be kept away from coloured liquids; the CIBJO Gemstone Book 2022 heading reads tortoiseshell, and another book from the same publisher states word for word that the best tortoiseshell comes from the hawksbill turtle, so the correspondence with tortoiseshell is given by the original texts themselves, not by this site's judgement.
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”.
Durability
Hawksbill Turtle Shell — 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
- Qualification
The cited clause covers tortoiseshell and names this entry as its common designation.
Source & check 2026-09-20
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.9 (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Hawksbill Turtle Shell — stability: low hardness, so it scratches easily; porous, so keep it away from coloured liquids.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code a, special-care code c
- Treatment state
- untreated
- Qualification
The row we cite is headed tortoiseshell; the same publisher states in another volume that the finest tortoise shell comes from the hawksbill turtle, so the match to this entry comes from the source, not from us.
Source & check 2026-09-21
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Tortoiseshell, p.80; §6.2 a, c (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.
Testing and market
The CIBJO laboratory protocol covers Hawksbill Turtle Shell under “Turtle Shell” (§6.2.27): see identification on the Turtle Shell entry; the required tests are listed on the CIBJO laboratory protocol table for Turtle Shell.
How far testing can go
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Hawksbill Turtle Shell has one direct definition in Annex A of GB/T 16552—2017, with the registered English entry name Hawksbill Turtle Shell, defined as shell material from the hawksbill turtle (Eretmochelys imbricata). The cross-check result is that it is listed directly by GB/T, and no standalone CIBJO entry under the same name was found.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Hawksbill Turtle Shell | GB/T 16552-2017 Annex A | Shell material from hawksbill turtle (Eretmochelys imbricata) | Listed directly by GB/T; CIBJO carries no standalone entry under the same name. |
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 |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Hawksbill Turtle Shell 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.