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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
Blue Coral
Also known asBlue Ridge Coral · Blue Sponge Coral · Denim Coral
Heliopora coerulea, a reef-building coral of the blue coral family; it is calcareous and is a common coral, not a Precious Coral. Its skeleton is rough and porous, so it is usually impregnated with resin for use in ornaments. Also known as Blue Ridge Coral, Blue Sponge Coral.
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 Blue Coral forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify Blue CoralIdentification points from the research literature
- Blue Coral 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 Blue CoralThe listing name to use; what must be disclosed before sale
What we cannot conclude
- Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.
- Geographic origin, unless an origin report accompanies the item.
- Price, rarity or investment value: this wiki covers naming and disclosure only.
Material research: formation, causes and history
What authoritative sources say about how this material forms, what causes its colour and optical effects, where its name comes from and how people have used it. Each statement carries an evidence grade and its sources; it describes the material in general, not any specific piece.
How it forms
Blue coral refers to the species Heliopora coerulea, a calcareous reef-building octocoral (a common coral). It is formed of biomineralized calcium carbonate secreted by coral polyps: the Helioporacea form massive skeletons of fibro-crystalline aragonite fused into lamellae, structurally similar to those of the Scleractinia (stony corals). Blue coral has a distinct blue colour and a rough, porous skeleton that usually requires resin impregnation when used as an ornament. It lives in shallow Indo-Pacific waters; because it builds reefs it is protected, and it is now rarely met as a gem material. Per SPECIES+, Heliopora coerulea is currently listed in CITES Appendix II (effective 18/01/1990, excluding fossils).
Scope: Applies to explaining the biogenic origin, composition, occurrence and CITES Appendix II status of blue coral (Heliopora coerulea) as a calcareous reef-building octocoral; not applicable to determining the locality, treatment or value of a specific sample from the name.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet · Coral Reefs (2021) +1
- CIBJO Blue Book — Coral Book (Coral Commission 2024)
- CIBJO Information Sheet: Background about Coral for Educators
- Linear extension, skeletal density, and calcification rates of the blue coral Heliopora coerulea (Coral Reefs, 2021)
- Checklist of CITES Species (checklist.cites.org), consulted 2026-10-03 and re-checked 2026-10-05
Where it forms
Indo-Pacific shallow-water, reef-building setting.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
A protected reef-building coral, hardly seen today as a gem material.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
How it forms, step by step
Coral polyps (a colony) grow.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
They secrete biomineralized aragonite, forming a massive fibro-crystalline skeleton with aragonite fused into lamellae.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
The skeleton is rough and porous and usually requires resin impregnation when used as ornaments.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
Link to appearance
It has a distinct blue colour and a rough, porous skeleton; but appearance cannot substitute for species identification, and the species is protected and rarely seen as gem material.
Sources CIBJO Coral Blue Book 2024 · Coral Reefs (2021) · CITES Checklist
Timescale
The cited sources give no absolute age for blue coral; NOAA research gives linear extension and calcification rates (e.g. linear extension about 0.86 cm/yr) but no absolute age.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet · Coral Reefs (2021) +1
- CIBJO Blue Book — Coral Book (Coral Commission 2024)
- CIBJO Information Sheet: Background about Coral for Educators
- Linear extension, skeletal density, and calcification rates of the blue coral Heliopora coerulea (Coral Reefs, 2021)
- Checklist of CITES Species (checklist.cites.org), consulted 2026-10-03 and re-checked 2026-10-05
Supporting findings
Blue coral (Heliopora coerulea) is a reef-building octocoral (a common coral) that secretes biomineralized calcium carbonate to form its skeleton.
Evidence grade AScope: A biogenic-process statement; a given sample's species (which should be H. coerulea) should still be verified.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
Blue coral occurs in Indo-Pacific shallow waters, is a reef-building coral, is protected, and is hardly seen today as a gem material.
Evidence grade AScope: An occurrence and protection-status description; not tied to any specific sample's origin.
Sources CIBJO Coral Blue Book 2024 · CIBJO Coral Information Sheet
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
- Indo-Pacific shallow watersProtected reef-building coral, hardly used as gem material today
Sources CIBJO Coral Blue Book 2024
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 the origin determination guide and the overview of recorded localities.
How it is identified
The appearance of blue-coral can be imitated, so appearance alone cannot confirm it. Imitation coral lacks the chemical composition, physical properties or structure of natural coral; identification requires laboratory methods — examining internal features such as the different polished lustre of filled fissures at 10× magnification, together with instrumental testing of chemistry and structure — while dyed, filled, impregnated and coated treatments must be detected and disclosed at sale. Limitations: some treatments and imitations are visible only under magnification or instrumentation, and the conclusion must be issued by an accredited gemological laboratory through testing rather than inferred from appearance.
Evidence grade AScope: Identification and separation points; testing must be performed by an accredited gemological laboratory, and no self-test thresholds are given.
Sources CIBJO Coral Blue Book 2024 · CIBJO Gemstone Book 2022
Other research findings
Blue coral is of calcareous composition; Helioporacea form massive fibro-crystalline aragonite skeletons with aragonite fused into lamellae, structurally similar to stony corals.
Evidence grade AScope: Skeletal composition and structure of blue coral (Helioporacea); not a quantitative analysis of any sample.
Sources CIBJO Coral Blue Book 2024
Per the CITES Checklist, Heliopora coerulea is in CITES Appendix II (effective 18/01/1990, excluding fossils); trade legality depends on species and permits.
Evidence grade AScope: The species' CITES level; current status updated at CoPs, and 'protected' is not a blanket trade ban.
Sources CITES Checklist · CIBJO Coral Blue Book 2024
Blue coral has a rough, porous skeleton that usually requires resin impregnation when used as an ornament; its skeleton has relatively high density and is relatively resistant to thermal stress.
Evidence grade AScope: A material-property and ecological-tolerance description; not a sourcing or conservation recommendation.
Sources CIBJO Coral Blue Book 2024 · Coral Reefs (2021)
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- Blue coral corresponds to the single species Heliopora coerulea, so it is treated as a material in its own right; it is a biogenic material, not a mineral species.
- CITES Appendix II (effective 18/01/1990, excluding fossils); 'protected' is not a blanket trade ban—legality depends on species and permits.
- The cited sources give no absolute age; the extension/calcification rates are research data, not gemmological identification criteria.
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
- Blue coral (state the species and CITES papers)
CIBJO Coral Blue Book 2024 §5.13 “Blue coral”, Annex C §7.9.3 · CITES Appendices 2026 “HELIOPORIDAE”
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
"Blue Coral" is a market name rather than a mineral species name; before using it, verify: Laboratory identification required before the name is used.
Evidence
- CIBJO · 5.13
What this means for you
Before buying, check the recommended listing name "Blue coral (state the species and CITES papers)" 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
- 2026-09-26
Trade-name ruling
- Laboratory identification required before the name is used.
- Suggested listing name
- Blue coral (state the species and CITES papers)
Care and wear
No care facts are recorded for this entry itself. Its parent material has care records: see Coral.
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Blue Coral, the name register records "Blue Ridge Coral", "Blue Sponge Coral" and "Denim Coral", for which no restriction on use as a name is recorded.
Standard and listing namesThe GB/T 16552—2017 naming counterpart for Blue Coral is coral (Table A.3); the name itself is not listed in the standard. The suggested listing name is Blue Coral (stating the species and permit documents). Trade and mineralogical namesThe mineralogical name is Blue coral (Heliopora coerulea), a calcareous, reef-building octocoral and a common coral. Trade names or synonyms are Blue Ridge Coral, Blue Sponge Coral and Denim Coral, all registered as market names. Names in four languagesNames are registered in four languages: Simplified Chinese, Traditional Chinese, English (Blue Coral) and Japanese (pending verification); the Japanese name shown is the entry's own and is pending verification, and the wording used by the GSJ (Japan) for it is not yet verified by this site. Institution usageOn authority wording, CIBJO records Blue Coral (CIBJO Coral Blue Book 2024), the FTC text on file has no wording for this name (checked), and GIA and Gem-A are unchecked; bodies without a recorded wording show the English name of Blue Coral, which does not represent their position.
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) | ||||
| Blue Ridge CoralEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| Blue Sponge CoralEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| Denim CoralEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 青珊瑚（待核） (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)
- 珊瑚 (GB/T 16552—2017 Table A.3)
- Mineralogical name
- Blue coral (Heliopora coerulea): calcareous reef-building octocoral, a common coral
- Trade names and synonyms
- Blue Ridge Coral (market name) · Blue Sponge Coral (market name) · Denim Coral (market name)
Four-language names
- 简体中文
- 蓝珊瑚
- 繁體中文
- 藍珊瑚
- English
- Blue Coral
- 日本語
- 青珊瑚（待核）
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural organic and biogenic materials
- Browsing family
- Coral 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
Among the registered material facts for Blue Coral, composition (phase) is calcareous, that is, calcium carbonate; this entry comes from the Coral Book of the CIBJO Blue Book (2024).
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
Blue Coral — composition (phase): calcareous (calcium carbonate)
CIBJO Coral Blue Book 2024
Source & check 2026-09-26
- Source
- CIBJO Blue Book — Coral Book (Coral Commission 2024) (CIBJO): §5.13 (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.
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.
- CIBJO – The World Jewellery Confederation. The Coral Book (Blue Book), 2024.
- CITES Secretariat. Appendices I, II and III, valid from 5 March 2026.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- eCFR (United States). 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 Coral 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 (Blue Coral) is marked.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Coral materials | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Blue Coral 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. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.