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Natural organic and biogenic materials · Organic or biogenic material · Natural identity; treatment status unknown
Natural Conch Pearl / Natural Melo Pearl
Also known asconch pearl
A non-nacreous pearl from conch or Melo snails, listed as "Conch Pearl" in GB/T Annex A Table A.3; the source mollusc must be stated. 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 Natural Conch Pearl / Natural Melo Pearl forms and what gives its colourFormation setting, process and timescale; where its colour and optical effects come from, each finding graded and sourced
- How to identify Natural Conch Pearl / Natural Melo PearlHow far lab testing can go
- Caring for and wearing Natural Conch Pearl / Natural Melo PearlCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of Natural Conch Pearl / Natural Melo PearlEach value with its source and check date
- Natural Conch Pearl / Natural Melo Pearl 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 Natural Conch Pearl / Natural Melo PearlThe listing name to use; what must be disclosed before sale
- Standard clauses that define Natural Conch Pearl / Natural Melo PearlWhich 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
A conch pearl is a non-nacreous (porcelaneous) natural pearl produced by gastropods such as the queen conch Strombus gigas or Melo melo; the exact type must be specified. Unlike nacreous pearls built from layered aragonite-rich nacre, conch pearls have a porcelaneous surface that may show flame structures and are usually composed of aragonite only. They are natural: the mollusc itself secretes calcium carbonate around an irritant, with no implanted bead or grafted tissue. Because of their non-nacreous structure, conch pearls must be distinguished from nacreous pearls and from imitations, and their mollusc source must be stated.
Scope: Applies to explaining the genesis and identification boundaries of non-nacreous natural pearls from gastropods (conch pearls, Melo pearls, etc.); does not apply to nacreous pearls, cultured pearls or imitation pearls.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
Where it forms
Tropical to subtropical seas, formed by gastropods; the queen conch (Strombus gigas) is a typical source.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
Within the gastropod's shell or soft tissue, by the mollusc's own calcium-carbonate secretion around an irritant, with no human intervention.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
How it forms, step by step
An irritant enters the gastropod's soft tissue or shell interior.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
The mollusc secretes calcium carbonate around the irritant—usually aragonite in conch pearls—with no implantation.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
The carbonate builds in a non-nacreous (porcelaneous) manner, producing a surface lacking nacre layers and often showing flame structures.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
A conch pearl results; its exact type (conch, Melo, etc.) requires gemological identification.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
Link to appearance
Conch pearls and other non-nacreous pearls typically show a porcelaneous surface marked by flame structures, unlike the layered luster seen in nacreous pearls.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
Timescale
The available authoritative sources give no growth duration or age for conch pearls.
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
Related base materials
- Natural pearl (broadly): non-nacreous-variant | Often listed alongside natural pearls, but is a non-nacreous (lacking a nacre layer) natural pearl, produced by gastropods rather than nacreous bivalves such as oysters
Recorded localities
This is an organic material; its localities are the harvest or culture areas (waters or species ranges) recorded by authoritative sources.
North America
- Bermuda
Sources Gems & Gemology Winter 1987
- Southeast coast of Florida and the Florida Keys, United Statestext concerns the conch's range; Florida may also have been a source
Sources Gems & Gemology Winter 1987
- Eleuthera and Exuma Islands, BahamasG&G quoting Sinkankas: before 1900 demand was largely met from here
Sources Gems & Gemology Winter 1987
Seas and coasts
- Caribbean SeaG&G: found only in the waters of the Caribbean and Bermuda
Sources Gems & Gemology Winter 1987 · CIBJO Pearl Book 2024
- The History and Gemology of Queen Conch "Pearls" (G&G Winter 1987)
- CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1)
These are localities recorded by authoritative sources, not an origin finding for any individual piece. The CIBJO Gemstone Book (2022, §4.2.3) says a place of origin names where a gem was mined or harvested, is a matter of opinion, does not imply a level of quality, and that cutting, processing or exporting centres must not be used to imply origin. See how far testing can go on this page, the origin determination guide and the overview of recorded localities.
Causes of colour and optical effects
Porcelaneous (non-nacreous) pearls have a porcelain-like surface and may show flame structures.
Evidence grade BScope: Observational description of non-nacreous pearl surfaces; flame structure is an appearance feature, not a formation mechanism.
Other research findings
Pearls of the non-nacreous kind — from scallops, Cassis, Melo melo, clams and conch — are frequently sent to GIA for identification; the conch pearl is one of these types, and the type must always be specified.
Evidence grade AScope: Classification/identification boundary; the source lists types without a per-type formation mechanism.
Conch or clam pearls are usually composed of aragonite only, unlike the Spondylus pearls studied, which contained both aragonite and calcite.
Evidence grade BScope: Laboratory-experience comparison (Raman spectroscopy); individual exceptions are not excluded.
A conch pearl is a non-nacreous natural pearl from a gastropod, structurally distinct from nacreous pearls produced by bivalves such as oysters.
Evidence grade AScope: Directly defined by CIBJO Pearl Book 2024 clause 5.48: a conch pearl is a non-nacreous natural pearl produced by gastropods such as the Queen Conch (Aliger gigas).
Sources G&G Fall 2014 · CIBJO Pearl Book 2024
CIBJO's definition treats a conch pearl as a natural pearl of the non-nacreous class. Its calcium carbonate is laid down concentrically in a crossed-lamellar microarchitecture, a structure that typically yields a porcelaneous sheen together with a flame-like pattern on the surface. Gastropods of various kinds, among them the Queen Conch (Aliger gigas), are the producers.
Evidence grade AScope: The naming/formation clause (5.48); defines a conch pearl by its non-nacreous microarchitecture, flame pattern and gastropod origin.
Sources CIBJO Pearl Book 2024
Limits of this research
- Research status: Only partial material-specific findings found; gaps are stated as gaps
- A conch-specific naming and formation definition is now provided by CIBJO Pearl Book 2024 clause 5.48; the original Spondylus pearl source is used only for comparison.
- No growth duration or age for conch pearls.
- Per-type criteria distinguishing conch from Melo pearls are not given in the source; the type must be specified.
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
- Non-nacreous natural pearl (state Conch or Melo)
GB/T 16552—2017 Table A.3 “Conch Pearl,Melo Pearl” · CIBJO Pearl Book 2024 §5.48
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
"Natural Conch Pearl / Natural Melo Pearl" 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 海螺珠 (Natural Conch Pearl / Natural Melo Pearl)
What this means for you
Before buying, check the recommended listing name "Non-nacreous natural pearl (state Conch or Melo)" 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
- Non-nacreous natural pearl (state Conch or Melo)
Care and wear
The normal and special care that applies to all natural and cultured pearls, and so to Natural Conch Pearl / Natural Melo Pearl (CIBJO Pearl Book §7.1, §7.2; the source says this advice counts as normal across the whole range and should be passed on to the buyer), is set out in full under care on the Pearl entry.
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
Besides Natural Conch Pearl / Natural Melo Pearl, the name register records "conch pearl", for which no restriction on use as a name is recorded (GB/T 16552—2017 Table A.3 “Conch Pearl,Melo Pearl”; CIBJO Pearl Book 2024 §5.48).
Standard and listing namesThe Chinese standard name for Natural Conch Pearl / Natural Melo Pearl is given in GB/T 16552—2017 Table A.3; it is a trade name, not a mineralogical species name, and the suggested listing name is conch pearl (stating Conch or Melo). Names in four languagesNames are registered in four languages: Simplified Chinese, Traditional Chinese, English (Natural Conch Pearl / Natural Melo Pearl) and Japanese. Trade and mineralogical namesThe mineralogical name describes a non-nacreous pearl from a conch or a Melo snail, and the type must be stated. Institution usageThe CIBJO Pearl Book 2024 covers this material item by item under “Conch Pearl”. The wording of GIA, FTC, CIBJO and Gem-A for Natural Conch Pearl / Natural Melo Pearl is not yet verified by this site; the entry's own English name is shown and does not represent the position of those bodies. Japanese namesThe Japanese name shown is the entry's own, and the wording used by the GSJ (Japan) for it is not yet verified by this site. Conch Pearl and Melo Pearl do not come from the same source, so the mollusc must be stated separately for each.
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 (1) | ||||
| conch pearlEnglish | synonym | matched automatically | no restriction recorded | GB/T 16552—2017 Table A.3 “Conch Pearl,Melo Pearl”; CIBJO Pearl Book 2024 §5.48 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- コンクパール／メロパール (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 海螺珠 (GB/T 16552—2017 Table A.3)
- Mineralogical name
- Non-nacreous pearl from conch or Melo molluscs; type must be specified
- Trade names and synonyms
- conch pearl (synonym)
Four-language names
- 简体中文
- 海螺珠
- 繁體中文
- 海螺珠
- English
- Natural Conch Pearl / Natural Melo Pearl
- 日本語
- コンクパール／メロパール
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural organic and biogenic materials
- Browsing family
- Pearl and molluscan shell 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
Material facts registered for Natural Conch Pearl / Natural Melo Pearl under GB/T 16553—2017: the inorganic part is CaCO3, mainly aragonite; the inorganic part is orthorhombic (aragonite), with minute aragonite platelets growing alternately with layers of organic matter, and the organic part is amorphous; Mohs hardness 3.5–4.5. Density is 2.81–2.87 g/cm³, and this site notes that the range is converted from the cited clause value of 2.85 with the tolerance (+0.02, −0.04); the clause also gives finer bands, with the overall value taken. Optic character is aggregate; refractive index is 1.51–1.68, and this site notes that the cited clause gives readings by the spot method, typical values rather than absolute limits, and that the clause gives finer bands, with the overall value taken; birefringence is not measurable in aggregates. For untreated conch pearls, the quality factor (lustre) is pearly to vitreous. In the UV-visible spectrum, red to pink samples show an absorption band near 520nm.
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
Natural Conch Pearl / Natural Melo Pearl: a non-nacreous natural pearl consisting of calcium carbonate arranged concentrically in a crossed lamellar microarchitecture. This structural characteristic usually produces a flame-like surface pattern and porcelaneous sheen. Such pearls are produced by various gastropods including the Queen Conch (Aliger gigas, also known as Lobatus gigas and Strombus gigas) (9.38), Horse Conch (Triplofusus giganteus formally known as Pleuroploca gigantea) (9.83), and the Emperor Helmet (Cassis madagascariensis) (9.12). Also, known as pink pearls. See also (9.15) conch. Note: see Clause 2 Normative References; Convention on International Trade in Endangered Species of Wild Fauna and Flora.
CIBJO Pearl Book 2024
- Qualification
CIBJO trade definition from an institutional manual, not a national standard. The English text quotes the full definition at §5.48 of the Pearl Book 2024.
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §5.48, p.27 (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Natural Conch Pearl / Natural Melo Pearl — composition (chemistry): inorganic part CaCO3, chiefly as aragonite
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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Structure
Natural Conch Pearl / Natural Melo Pearl — structure (overall): inorganic part: the orthorhombic system (aragonite), with aragonite micro-plates and organic lamellae growing in alternation. Organic part: non-crystalline.
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): §5.3.3 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Durability
Natural Conch Pearl / Natural Melo Pearl — Mohs hardness: 3.5–4.5
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): §5.3.3 (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Natural Conch Pearl / Natural Melo Pearl — cleavage: generally not seen 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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
stability2 sources compared
Natural Conch Pearl / Natural Melo Pearl — stability: effervesces in 5% HCl; the colour fades after long exposure to sunlight.
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): §5.3.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Natural Conch Pearl / Natural Melo Pearl — stability: Keep it away from all solvents and acids; no high temperatures and no ultrasonic cleaning; its colour may fade or change after long periods in sunlight or brief exposure to x-rays.
CIBJO Pearl Book 2024
- Treatment state
- untreated
Source & check 2026-09-21
- Source
- CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §7 Annex B, 7.2 and 7.2.2 Note, p.49 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Physical properties
Natural Conch Pearl / Natural Melo Pearl — density: 2.81–2.87 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 2.85, with a stated tolerance of +0.02 / -0.04. The range shown here is worked out from that.
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Natural Conch Pearl / Natural Melo Pearl — 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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — refractive index: 1.51–1.68
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives this as a value read by the spot (distant-vision) method. It is a common value, not an absolute limit.
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — 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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — 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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — fluorescence (overall): red to pink-red: long wave weak to moderate, pink-red, orange-red, yellow.
GB/T 16553—2017
UV fluorescencepink-redorange-redyellowweak–moderate, red to pink-redDots 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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — spectrum (UV-visible): red to pink-red: approximately 520 nm absorption band.
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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — spectrum (infrared): Carbonate-ion vibration in aragonite produces the diagnostic mid-IR bands
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): §5.3.3 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Natural Conch Pearl / Natural Melo Pearl — magnification: flame-like pattern
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): §5.3.3 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Natural Conch Pearl / Natural Melo Pearl — body colour: pink red to purple red, yellow, brown and white.
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 Rhodochrosite, Balin Stone, Rhodonite and other variety clauses also name red or a reddish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.3.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Quality factors
Natural Conch Pearl / Natural Melo Pearl — quality factor (lustre): pearly to vitreous
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): §5.3.3 (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): 1.595 / 2.84; Closest values: 1Giant Clam Shell 1.605 / 2.79, 2Muscovite 1.58 / 2.8, 3Akoya Cultured Pearl 1.605 / 2.75, 4Sugilite 1.61 / 2.77, 5Saltwater Natural Pearl 1.605 / 2.73
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
- Melo pearl
a natural non nacreous pearl (5.141) found in one of the Melo sp. volutes (9.43, 9.44, 9.45, 9.46, and 9.47).
CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §5.119, p.34
Definitions are quoted verbatim from the cited CIBJO Blue Book; […] marks an excerpt, and the full definition is at the cited clause.
Pearl-producing molluscs (CIBJO Annex D): §9.5 Aliger gigas · §9.12 Cassis madagascariensis · §9.15 Conch · §9.22 Emperor Helmet · §9.30 Horse Conch · §9.38 Lobatus gigas · §9.43 Melo aethiopica · §9.44 Melo amphora · §9.45 Melo broderipii · §9.46 Melo georginae · §9.47 Melo melo · §9.74 Queen Conch · §9.83 Triplofusus giganteus
Testing and market
Identification leads for Natural Conch Pearl / Natural Melo Pearl are registered under the CIBJO laboratory protocol, each limited to what it applies to. For queen conch (Strombus) pearls, the protocol calls for particular checks: pink samples change colour on X-ray exposure; samples that are not the usual pink but white or orange to purple in tone may resemble other porcellaneous pearls and are also vulnerable to acid, and shell imitations must be watched for. For Melo pearls, the protocol calls for particular checks: orange samples change colour on X-ray exposure, may resemble other orange porcellaneous pearls and are vulnerable to acid, and reshaped samples and shell imitations must be watched for. The required tests for Natural Conch Pearl / Natural Melo Pearl and what each method covers are given in the protocol table on the laboratory testing page.
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: §6.2.10, §6.2.14.
How far testing can go
Natural Conch Pearl / Natural Melo Pearl — what the CIBJO laboratory protocol says to watch for: X-ray discolouration to pink samples, possible similarity to other porcellaneous pearls when not the usual pink colour (i.e., white, orange to purplish), damage by acids, shell imitations.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
- Applies only to
- pearls from Lobatus gigas (conch)
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Natural Conch Pearl / Natural Melo Pearl — what the CIBJO laboratory protocol says to watch for: X-ray discolouration to orange samples, possible similarity to other orange porcellaneous pearls, damage by acids, check for shaped examples, shell imitations.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
- Applies only to
- pearls from Melo species
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
The clause-level definition for Natural Conch Pearl / Natural Melo Pearl is recorded as Conch Pearl / Melo Pearl, against GB/T 16552-2017 Annex A, defined as a non-nacreous pearl from conch or Melo snails, whose type must be stated. The cross-check result is listed directly by GB/T; CIBJO carries no standalone entry under the same name.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Conch Pearl / Melo Pearl | GB/T 16552-2017 Annex A | Non-nacreous pearl from conch or Melo molluscs; type must be specified | 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.
- CIBJO – The World Jewellery Confederation. The Pearl Book (Blue Book), 2024.
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 Pearl on this site: 17 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Natural Conch Pearl / Natural Melo Pearl) is marked.
- Pearl
Sub-entries (16)
- Abalone Pearl
- Akoya Cultured Pearl
- Baroque Cultured Pearl
- Blister Pearl
- Circled Cultured Pearl
- Cultured Pearl
- Freshwater Cultured Pearl
- Freshwater Natural Pearl
- Keshi Cultured Pearl
- Natural Conch Pearl / Natural Melo Pearl
- Natural Pearl
- Saltwater Cultured Pearl
- Saltwater Natural Pearl
- South Sea Cultured Pearl
- Tahitian Cultured Pearl
- White South Sea Cultured Pearl
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Pearl and molluscan shell materials | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Natural Conch Pearl / Natural Melo Pearl 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.