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
Golden Coral
Coral material with a golden colour; it may be natural gold coral or bleached black coral, so the cause of colour must be identified. 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 Golden Coral forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify Golden CoralIdentification points from the research literature; how far lab testing can go
- Treatments and enhancements of Golden CoralThe enhancements and treatments the GB/T and JJA/AGL tables list
- Caring for and wearing Golden CoralCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of Golden CoralEach value with its source and check date
- Golden Coral in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Has any of GIA, FTC, CIBJO or Gem-A put a name for it on record here?
- Listing and disclosing Golden 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
"Golden coral" has two meanings in the CIBJO coral standard. First, natural golden coral (5.47): a common coral of a natural golden colour with a non-calcareous skeleton, belonging to two taxonomic groups (the Primnoidae and Zoanthidae families, notably Kulamanamana haumeaae). Second, bleached black coral (5.48): black coral (order Antipatharia, whose skeleton is composed of protein and chitin) bleached to become golden. Golden coral is therefore not a single species or a single material type: it may be natural non-calcareous common coral, or it may come from treated black coral. Natural golden coral (Primnoidae) occurs at various depths, up to 1000 metres or more (Alaska), while the Zoanthidae Kulamanamana haumeaae lives at 340–580 metres in Hawaii. All corals of the order Antipatharia are listed in CITES Appendix II, and their trade requires permits.
Scope: Applies to an overview of the naming boundary of 'golden coral' in the CIBJO coral standard (natural golden coral vs bleached black coral), its skeletal properties, depth and CITES status; does not constitute an identification conclusion for a single species or material.
Sources CIBJO Coral Blue Book 2024
Where it forms
Natural golden coral (family Primnoidae) — at various depths, up to 1000 metres or more (Alaska).
Sources CIBJO Coral Blue Book 2024
The Zoanthidae Kulamanamana haumeaae — 340–580 metres in Hawaii.
Sources CIBJO Coral Blue Book 2024
Black coral (bleached to golden) — strong-current environments at depths up to about 6000 metres.
Sources CIBJO Coral Blue Book 2024
How it forms, step by step
Natural golden coral (Primnoidae/Zoanthidae) forms a non-calcareous skeleton on the seabed and is naturally golden.
Sources CIBJO Coral Blue Book 2024
The skeleton of black coral is composed of protein and chitin.
Sources CIBJO Coral Blue Book 2024
Bleaching black coral yields the golden colour, producing "golden coral (treated)".
Sources CIBJO Coral Blue Book 2024
Link to appearance
Natural golden coral is naturally golden with characteristic ring growth structures and may acquire a characteristic sheen after polishing; bleached black coral can also appear golden.
Sources CIBJO Coral Blue Book 2024
Timescale
The source gives no absolute timescale for the formation or growth of golden coral.
Sources CIBJO Coral Blue Book 2024
Related base materials
- Common coral (non-precious): Golden coral is a name for a category of common coral with a golden appearance
- Black coral (order Antipatharia): Golden coral may be bleached black coral
Supporting findings
Natural golden coral (family Primnoidae) occurs at various depths, up to 1000 metres or more (Alaska), while the Zoanthidae Kulamanamana haumeaae lives at 340–580 metres in Hawaii.
Evidence grade AScope: Habitat-depth description; individual colonies may fall outside the range.
Sources CIBJO Coral Blue Book 2024
Coral (including the groups to which golden coral belongs) comprises skeleton-bearing marine invertebrates of the phylum Cnidaria, formed by nature without human intervention.
Evidence grade AScope: A material-classification statement; classification here follows the CIBJO coral standard.
Sources CIBJO Coral Blue Book 2024
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
- Waters off Alaska, United StatesOne of the two natural golden corals (family Primnoidae)
Sources CIBJO Coral Information Sheet
- Waters off Hawaii, United StatesThe second natural golden coral (Kulamanamana haumeaae), 340–580 m deep
Sources CIBJO Coral Information Sheet
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.
How it is identified
Golden coral can closely resemble other corals, bone materials, and dyed or plastic imitations in colour and appearance, and the eye cannot reliably separate them. Its identity and treatment status must be judged in a laboratory, typically using microscopic structure and spectroscopic instruments; the cited sources only define nomenclature and classification and give no self-test criteria, so conclusions must come from an accredited laboratory.
Evidence grade AScope: Appearance cannot replace identification; a qualified laboratory test is required, and this entry gives no self-test criteria.
Sources CIBJO Coral Blue Book 2024
Other research findings
CIBJO 5.47 "golden coral" denotes a common coral of natural golden colour with a non-calcareous skeleton belonging to two taxonomic groups (Primnoidae and Zoanthidae, notably Kulamanamana haumeaae); it may also refer to bleached black coral (5.48). Golden coral is therefore not a single species or material type.
Evidence grade AScope: Naming and classification; distinguishes natural golden coral from treated black coral.
Sources CIBJO Coral Blue Book 2024
Black coral can be bleached to become golden — CIBJO 4.2.5.4 records "Black coral treated to golden by bleaching".
Evidence grade AScope: A treatment description; the treatment must be disclosed per CIBJO.
Sources CIBJO Coral Blue Book 2024
Black coral is a very dark brown to black common coral composed of protein and chitin (a non-calcareous skeleton); naturally golden coral is likewise non-calcareous.
Evidence grade AScope: Describes skeleton composition; distinct from calcareous precious coral.
Sources CIBJO Coral Blue Book 2024
All black corals of the order Antipatharia (including the genus Antipathes) are listed in CITES Appendix II and their trade requires an export permit; legality of origin depends on species and permits.
Evidence grade AScope: A CITES appendix fact; the legality of a specific transaction must be checked against permits case by case.
Sources CIBJO Coral Blue Book 2024
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- Single source (the CIBJO coral standard), focused on trade classification and nomenclature; it does not describe the physiology by which the polyps deposit the skeleton.
- The database flags this name as requiring identification and compliance review: because "golden coral" may denote natural common coral or bleached black coral, identification and compliance must be handled case by case.
- The source gives no absolute timescale for golden coral formation/growth.
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
- Golden Coral (state the species and any treatments)
16 CFR Part 23 §23.1 · CIBJO Coral Blue Book 2024 §5.28
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Bleached, Filled / Fracture-filled (via parent material), Coated (via parent material), Dyed (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
"Golden Coral" is a market name rather than a mineral species name; before using it, verify: Laboratory identification required before the name is used.
Evidence
What this means for you
Before buying, check the recommended listing name "Golden Coral (state the species and any treatments)" 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
- Golden Coral (state the species and any treatments)
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 normal care that applies to all corals, and so to Golden Coral (CIBJO Coral Book §6.1), and the special care the source gives for some corals without saying which ones (§6.2), are set out in full under care on the Coral entry.
Care
Golden Coral — 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
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Golden Coral, p.42; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Golden Coral — care (chemicals): porous, so do not let it come into contact with coloured fluids; dissolves on contact with solvents such as nail varnish remover; keep it away from all solvents and other strong chemicals.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code c, special-care code i
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Golden Coral, p.42; §6.2 c, i (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Golden Coral — care (wear): Some stones are prone to scratching due to low hardness. Wear them with care.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code a
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Golden Coral, p.42; §6.2 a (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Golden Coral — care (special care): assembled with polymers and dyed: special care (SC); avoid chemicals and solvents.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- dyeing, impregnation
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.IX, Gemstone Information Chart, Coral “Gold” D,I, CARE REQUIRED / SPECIAL ADVICE (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
CleaningAccording to the CIBJO Blue Book (Official Gemstone Book, Coloured Stone Commission 2022), Golden Coral must not be cleaned ultrasonically. ChemicalsGolden Coral is porous and should not come into contact with coloured liquids; solvents such as nail-polish remover can dissolve Golden Coral, so it should be kept away from all solvents and other harsh chemicals. WearGolden Coral is soft and scratches easily, so it should be worn with care. AGTAThe AGTA (American Gem Trade Association) Gemstone Information Manual, 17th edition, states that dyed and impregnated Golden Coral (assembled with polymer and dyed) needs special care and should be kept away from chemicals and solvents.
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 | porous, so do not let it come into contact with coloured fluids; dissolves on contact with solvents such as nail varnish remover; keep it away from all solvents and other strong chemicals |
| Wearing limits (knocks, settings) | care (wear) |
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.
any treatment state
- care (cleaning) §6.2 j
- porous, so do not let it come into contact with coloured fluids; dissolves on contact with solvents such as nail varnish remover; keep it away from all solvents and other strong chemicals §6.2 c, i
- care (wear) §6.2 a
treated (Only after these treatments: dyeing, impregnation)
Treatments and identification leads
One row per treatment, with three standards side by side: how often it occurs and how stable it is (CIBJO), its category in GB/T 16552—2017 Table B.1 (this site's paraphrase) and how the JJA/AGL 2025 table lists it. Each CIBJO value links to its entry under “Testing and market”, where the wording and source are given in full.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| Bleaching | — | — | Optimization | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Coating | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Dyeing | — | — | Treatment | — | — |
| bleached black coral | — | — | — | bleached black coral | — |
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Coral); 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
Standard and listing namesThe suggested listing name for Golden Coral is Golden Coral (state species/treatment). Under GB/T 16552—2017 Table A.3, the Chinese standard naming counterpart is coral, and the standard does not list Golden Coral. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Golden Coral) and Japanese; mineralogically it is coral of golden colour, which may come from bleached black coral or may be natural gold coral. Institution usageOn authority wording, the FTC text on file has no wording for Golden Coral, which has been checked; GIA, CIBJO and Gem-A wording is unchecked; for bodies without a recorded wording, the Golden Coral shown is the entry's own English name and does not represent their position. Japanese namesFor Japan's GSJ, the entry has its own Japanese name, and the wording of Japan's GSJ for Golden Coral is not yet verified by this site.
- GSJ (Japan) formal name
- 金色珊瑚 (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
- Coral with golden colour; may be from bleached black coral or natural gold coral
Four-language names
- 简体中文
- 金色珊瑚
- 繁體中文
- 金色珊瑚
- English
- Golden Coral
- 日本語
- 金色珊瑚
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
Treatments listed by standards
GB/T Table B.1For Golden Coral, this site applies the "Coral" row of GB/T 16552—2017 Annex B, Table B.1: bleaching is an optimization; filling and coating are graded; dyeing is a treatment. What Table B.1 is, and the grades referred to for filling and coating, are on the Gem treatments page. JJA/AGL designationsIn the "principal gem names" table of the Japanese JJA/AGL Definitions and Nomenclature of Gems and Ornamental Materials, November 2025 revision, Coral is listed with species coral and colour brownish yellow, with the listed entry being decolourised from black coral (bleaching); the original does not name Golden Coral specifically, and Golden Coral is a related entry. How to read the JJA/AGL table is explained on the Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Under the “Coral” row of Table B.1: Bleaching Optimization; Filling Graded — see §5.4.1, Table 1; Coating Graded — see §5.4.1, Table 1; Dyeing Treatment. The full row, with the effect column, is on the Coral 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 |
|---|---|---|---|---|
| Coral | Coral | brownish yellow | bleached black coral (Bleached) | listed under “Coral” in the table; this page is related (the source does not name it) |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.13
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
The material facts for Golden Coral take values by class. Registered for coral as a whole (calcareous and horny): the structure of calcareous coral is a cryptocrystalline aggregate in its inorganic part and amorphous in its organic part, while horny coral is amorphous; cleavage usually not seen in an aggregate; optic character aggregate; untreated, pleochroism not measurable for an aggregate; untreated, lustre waxy, vitreous on polished surfaces. Registered for horny coral: Mohs hardness 2–3, a range for the whole class rather than a measurement of Golden Coral, taken from the horny coral branch of the cited clause, and the CIBJO Coral Book states that Golden Coral is not calcareous; untreated, no reaction with hydrochloric acid; density 1.3–2.12 g/cm³ (derived from the clause value of 1.35 with tolerances of +0.77 and −0.05); refractive index 1.55–1.58 (derived from the clause value of 1.56–1.57 with a tolerance of ±0.01; a reading often obtained by the spot method, a common value rather than an absolute limit).
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”.
Chemical composition, luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for coral as a whole (calcareous and horny), horny coral, so they are not repeated on the Golden Coral page; see the material facts on the Coral entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Golden Coral (how to read class-level values).
Definition
Golden Coral: natural golden coloured non-calcareous varieties belonging to the Primnoidae family with characteristic ring growth structures that occur at various depths, up to 1000 meters or more, in Alaska, USA, and to the Zoanthidae family, notably Kulamanamana haumeaae, also with characteristic growth structures that lives at depths of 340-580 meters in Hawaii that, after polishing may acquire a characteristic sheen effect.
CIBJO Coral Blue Book 2024
- Qualification
Black coral may be treated to obtain a golden colour, so golden colour alone does not establish this identity.
Source & check 2026-09-22
- Source
- CIBJO Blue Book — Coral Book (Coral Commission 2024) (CIBJO): §7.9.5 (Annex B, normative), p.29 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Structure
Golden Coral — structure (overall): calcareous coral: the inorganic part is a cryptocrystalline aggregate and the organic part is non-crystalline. Horny coral: non-crystalline.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- coral as a whole (calcareous and horny)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Golden Coral — 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
- What this covers
- horny coral
- Qualification
This is the range for the whole class, not a measured value for this variety. The value comes from the horny-coral branch of the cited clause; the CIBJO Coral Book describes this coral as non-calcareous.
Source & check 2026-09-20
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Golden Coral — cleavage: generally not seen on an aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- coral as a whole (calcareous and horny)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Golden Coral — stability: Hydrochloric acid has no effect on it
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- horny coral
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Golden Coral — density: 1.3–2.12 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- horny coral
- Qualification
The clause we cite gives 1.35, with a stated tolerance of +0.77 / -0.05. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Golden Coral — optic character: aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- coral as a whole (calcareous and horny)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Golden Coral — refractive index: 1.55–1.58
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- horny coral
- 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. The clause we cite gives 1.56–1.57, with a stated tolerance of ±0.01. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Golden Coral — pleochroism: not measurable on an aggregate
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- coral as a whole (calcareous and horny)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Quality factors
Golden Coral — quality factor (lustre): waxy; polished surfaces take a vitreous lustre.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- coral as a whole (calcareous and horny)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.4 (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): 1.565 / 1.71; Closest values: 1Mammoth Ivory 1.53 / 1.75, 2Ivory 1.535 / 1.85, 3Coral 1.57 / 2, 4Plastic 1.58 / 1.3, 5Turtle Shell 1.545 / 1.31
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
Related CIBJO terms
- Golden coral
common coral of a natural golden colour and non-calcareous skeleton belonging to two taxonomic groups (e.g. Primnoidae family and Zoanthidae family, notably Kulamanamana haumeaae). It may be treated black coral (5.12).
CIBJO Blue Book — Coral Book (Coral Commission 2024) (CIBJO): §5.47, p.16
- Golden coral (treated)
black coral (5.12) bleached to become golden colour.
CIBJO Blue Book — Coral Book (Coral Commission 2024) (CIBJO): §5.48, p.16
Definitions are quoted verbatim from the cited CIBJO Blue Book; […] marks an excerpt, and the full definition is at the cited clause.
Testing and market
The CIBJO laboratory protocol covers Golden Coral under “Coral” (§6.2.4): see identification on the Coral entry; the required tests are listed on the CIBJO laboratory protocol table for Coral.
How far testing can go
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.
- 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 § 23.1 — Deception (general). 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 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 (Golden Coral) is marked.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Coral materials | Live |
| Treatments recorded for this material | Bleached, Filled / Fracture-filled (via parent material), Coated (via parent material), Dyed (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Golden 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.