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Natural organic and biogenic materials · Organic or biogenic material · Cultured formation; treatments recorded separately

South Sea Cultured Pearl

Also known asSouth Sea pearl (not to be used as a name)

Cultured pearls from Pinctada maxima, mostly white, silver or golden; the FTC limits their growing areas to South Pacific islands, Australia or Southeast Asia. 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.

Edited by JuneReviewed by RalphLast updated 2026-10-12Who maintains this page

Care and wear

What this page can answer

This page covers

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

Layers, outside to centre:

  1. nacre
  2. bead nucleus
Schematic cross-section of South Sea Cultured Pearl, outside to centre: nacre, bead nucleus
South Sea Cultured PearlSchematic, not to scaleDrawn from the construction recorded under “Material research” on this page; assembly method not drawn (source: G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1)If you reuse this image, please credit LumaLark Wiki and link to this pageLicense: CC BY 4.0

South Sea cultured pearls are bead cultured pearls grown in the Pinctada maxima oyster (the silver- or gold-lipped pearl oyster), often marketed as South Sea. Cultivation follows the general saltwater bead-culture process: a technician implants a piece of mantle tissue (saibo) from a donor together with a shell bead—usually made from a freshwater mussel shell—into the host mollusc's gonad; the mantle epithelium multiplies, forms a cultured pearl sac around the bead, and continuously deposits nacre onto it. P. maxima, the largest member of its genus, normally needs a growth period of at least two years and produces the thickest nacre of any bead cultured pearl, which is why South Sea pearls are prized for large size and thick nacre.

Scope: Applies to explaining the cultivation and colour origin of beaded cultured pearls from Pinctada maxima (South Sea cultured pearls); not applicable to natural pearls or cultured pearls from other host molluscs.

Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

Where it forms

Marine farms between the Tropics of Cancer and Capricorn, matching the native distribution of P. maxima.

Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

Australia produces white pearls from silver-lipped shells; Indonesia, Myanmar and the Philippines produce golden pearls from gold-lipped shells.

Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

In the host gonad, within a cultured pearl sac formed by implanted mantle epithelium.

Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

How it forms, step by step

  1. A small piece of mantle tissue (saibo) is taken from a donor of the same species, and a shell bead nucleus (usually from freshwater mussel shell) is prepared.

    Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

  2. The bead and mantle tissue are implanted together into the gonad of the host P. maxima mollusc (bead culture).

    Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

  3. The mantle epithelium multiplies and encloses the bead, forming a cultured pearl sac.

    Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

  4. The pearl sac continuously secretes nacre onto the bead, and over at least about two years the South Sea cultured pearl forms.

    Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description +1

Link to appearance

The colour of P. maxima cultured pearls depends on the oyster type—silver-lipped shells yield white/silver, gold-lipped shells yield golden; what the resulting pearl's nacre looks like frequently mirrors the shade of the mother-of-pearl layer, and large size together with thick nacre sets these pearls apart.

Sources GIA Pearl Description · G&G Spring 2013

Timescale

Bead cultured pearls with the thickest nacre come from P. maxima, which normally needs at least two years of growth.

Sources G&G Fall 2021

Related base materials

  • Cultured pearl: cultured-pearl-type-by-mollusc | Cultured pearl category defined by the host mollusc (the large pearl oyster Pinctada maxima)

Supporting findings

Saltwater cultured pearls are grown by implanting a bead nucleus together with mantle tissue (saibo) from a donor mollusc into the host mollusc's gonad.

Evidence grade A

Scope: General saltwater bead-culture procedure, applicable to Pinctada hosts such as P. maxima.

Sources G&G Fall 2021 · G&G Spring 2013 · GIA Pearl Description

South Sea cultured pearls come from Pinctada maxima; silver-lipped shells are found mostly south of the equator and gold-lipped shells to the north.

Evidence grade A

Scope: Mollusc species and lip-colour geography from GIA research; producing countries are the main commercial sources.

Sources CIBJO Pearl Book 2024 · G&G Fall 2021 · GIA Pearl Description

To yield bead cultured pearls with the thickest nacre, P. maxima normally needs a growth period of at least two years.

Evidence grade A

Scope: General growth period for P. maxima bead culture; individual duration varies with environment and management.

Sources G&G Fall 2021

Recorded localities

This is an organic material; its localities are the harvest or culture areas (waters or species ranges) recorded by authoritative sources.

Locality sketch mapLand outlines only; the map does not depict any national or regional boundary. Dots mark approximate positions. Base map: Natural Earth (public domain).

Asia

  • IndonesiaOrganic harvest or culture area · Principal source
    Sources CIBJO Pearl Book 2024 · GIA Pearl Description
  • PhilippinesOrganic harvest or culture area · Principal source
    Sources CIBJO Pearl Book 2024 · GIA Pearl Description
  • MyanmarOrganic harvest or culture area
    Sources CIBJO Pearl Book 2024
    • CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1)

Oceania

  • Northern Australia coastOrganic harvest or culture area · Principal source
    Sources CIBJO Pearl Book 2024 · GIA Pearl Description

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

The colour of cultured pearls from P. maxima ranges from white through silver to golden, governed by which oyster variety is used; when allotransplanted, P. maxima normally yield pearls that are white to light gray, silver, cream or yellow to golden.

Evidence grade A

Scope: Colour-oyster/donor association is supported; pigment-level causes are not detailed.

Sources GIA Pearl Description · G&G Spring 2013

How it is identified

South Sea cultured pearls can resemble natural pearls, other cultured pearls, and dyed or imitation pearls in appearance, so unaided inspection cannot reliably decide whether they are cultured or treated. Determination relies on laboratory testing, typically real-time X-radiography, real-time microradiography for measuring nacre thickness, UV-visible reflectance spectroscopy, X-ray fluorescence, and computed micro-tomography (μCT) for loose pearls. Pearl type and the detectability of treatment must be judged by an accredited laboratory, and this entry provides no self-test threshold.

Evidence grade A

Scope: Appearance is insufficient to decide cultured or treated status; determination requires testing by an accredited laboratory, and this entry gives no self-test method or threshold.

Sources GIA: How GIA Identifies Pearls · CIBJO Pearl Book 2024

Other research findings

South Sea cultured pearls are cultured pearls grown with human implantation of a bead and tissue, distinct from natural pearls.

Evidence grade A

Scope: Conceptual cultured-vs-natural boundary; not a per-sample identification.

Sources GIA Pearl Description · GIA: How GIA Identifies Pearls

CIBJO's Pearl Book 2024 defines a South-sea cultured pearl (5.186) as one grown in Pinctada maxima; 'South-sea' (5.185) names the region lying between Myanmar and Northern Australia that also takes in Indonesia and the Philippines and forms the habitat of the Pinctada maxima oyster.

Evidence grade A

Scope: Naming and origin definition per CIBJO 5.186/5.185; distinct from natural South Sea pearls.

Sources CIBJO Pearl Book 2024

South Sea cultured pearls are assessed by lustre, nacre thickness, surface, shape, colour and matching, consistent with GIA's seven Pearl Value Factors. They are bead-nucleated, so nacre thickness is a measurable factor tied to the culturing period and affecting colour, lustre and durability, but thickness does not equal nacre quality; assessment pays more attention to a substantial nacre layer, lustre and surface. The emphasis differs from freshwater cultured pearls: bead-cultured saltwater pearls weigh nacre thickness, while most freshwater pearls are beadless and that measure usually does not apply. Imitation pearls are not subject to pearl quality assessment.

Evidence grade A

Scope: Quality factors describe which characteristics the market generally prizes; they are not a grade for any specific specimen and are neither price nor investment advice. Pearl quality assessment must be issued by an accredited laboratory for a specific specimen.

Sources CIBJO Pearl Book 2024 · GIA: How GIA Identifies Pearls

Limits of this research

  • Research status: Formation, occurrence or other material-specific findings found in authoritative sources
  • Colour cause is supported only at the level of oyster type / donor tissue determining colour; no pigment-level mechanism is given.
  • The bead source (freshwater mussel shell) is a general practice, not universal for every South Sea pearl.

Methodology

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
South Sea Cultured Pearl

16 CFR Part 23 §23.21(g), §23.20(b)

Construction or treatment status

Cultured formation; treatments recorded separately

Treatments recorded for this material: Bleached (via parent material), Dyed (via parent material), Irradiated (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

South Sea Cultured Pearl is Cultured pearl from the Pinctada maxima oyster; primarily white, silver or golden; use "South Sea Cultured Pearl" for listings, and disclose any known treatments.

Evidence

What this means for you

Before buying, check the recommended listing name "South Sea Cultured Pearl" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.

Known uncertainty

Last reviewed
2026-09-01

Care and wear

The normal and special care that applies to all natural and cultured pearls, and so to South Sea Cultured 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

South Sea Cultured Pearl — care (light): may fade or revert to its original colour, so it should not be left for long periods in strong natural or artificial light or under strong display lighting.

CIBJO Pearl Book 2024

Treatment state
treated
Only after these treatments
coating, dyeing
Source & check 2026-09-26
Source
  • CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §8.2 Annex C, South-sea Cultured Pearl, p.54; §7.2, §7.2.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — care (wear): breaks easily, so it is not meant for everyday wear and should not be worn during heavy work.

CIBJO Pearl Book 2024

Treatment state
treated
Only after these treatments
filling
Source & check 2026-09-26
Source
  • CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §8.2 Annex C, South-sea Cultured Pearl, p.54; §7.2, §7.2.1 (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

Care for South Sea Cultured Pearl: the general and specific care listed in the CIBJO Pearl Book applies to both natural and cultured pearls, and so also to South Sea Cultured Pearl, and is listed in full in the care part of the Pearl entry; the CIBJO Pearl Book states that the care advice should be treated as standard for all pearls and passed on to the buyer. Light and displayOn light and display, for coated or dyed South Sea cultured pearls only: they may fade or revert to their original colour and should not be left for long periods in strong natural light, strong artificial light or strong display lighting. WearOn wear, for filled South Sea cultured pearls only: they break easily, are not meant for everyday wear and should not be worn during heavy physical work.

This table scrolls sideways on narrow screens.

QuestionMatching entries
Light and displaymay fade or revert to its original colour, so it should not be left for long periods in strong natural or artificial light or under strong display lighting
Wearing limits (knocks, settings)breaks easily, so it is not meant for everyday wear and should not be worn during heavy work

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.

treated (Only after these treatments: coating, dyeing)

treated (Only after these treatments: filling)

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.

TreatmentMarket frequency (CIBJO)Stability (CIBJO)GB/T 16552 categoryJJA/AGL listingIdentification leads
Bleaching——Optimization——
Dyeing——Treatment——
Irradiation——Treatment——

“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Cultured Pearl)

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

For South Sea Cultured Pearl, "South Sea pearl" must not be used as a name (16 CFR Part 23 §23.21(k); CIBJO Pearl Book 2024 §4.4.1.1.2); one further name in a non-Latin script is listed in the name register below (1 with no restriction recorded on use as a name).

Recommended listing nameThe suggested listing name for South Sea Cultured Pearl is South Sea Cultured Pearl. Names in four languagesThe names are given in Simplified Chinese, Traditional Chinese, English (South Sea Cultured Pearl) and Japanese, and the Japanese GSJ formal name is the Japanese name. Chinese standard nameThe GB/T naming counterpart is “Saltwater Cultured Pearl” (GB/T 16552—2017 Table A.3, row “Saltwater cultured pearl (seawater pearl)”; the GB/T text does not list South Sea Cultured Pearl). Sub-names and unacceptable namesThe trade name or synonym South Sea pearl is a market name and is not acceptable as a name, with “Pearl” as a related high-risk name; there is also the subordinate name saltwater pearl from Pinctada maxima (the white-lipped pearl oyster). Institution usageGIA lists South Sea Cultured Pearl, the FTC lists Cultured Pearl, and CIBJO lists South Sea Cultured Pearl; Gem-A has not been checked, and the entry's own English name is shown for it, which does not represent Gem-A's position. The FTC's qualifier is that the name is defined and “cultured” must not be omitted; CIBJO's qualifier is that the CIBJO Pearl Book states cultured is not natural. National standard namesGermany (RAL) writes Südsee-Zuchtperle and the EU South Sea Cultured Pearl, noting that Zuchtperle means cultured.

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.

NameTypeMatchingUse as a nameBasis
no restriction recorded (1)
大珠母贝（白蝶贝）海水珍珠Simplified Chinesenarrower name (variety or subtype)matched automaticallyno restriction recordedGB/T 18781—2023 3.2.1
not to be used as a name (1)
South Sea pearlEnglishmarket namematched automaticallynot to be used as a name16 CFR Part 23 §23.21(k); CIBJO Pearl Book 2024 4.4.1.1.2; Note: Related high-risk name “Pearl”.

How each authority words this name: see Names › Authority wording.

Authority wording

GIA
South Sea Cultured Pearl
FTC
Cultured Pearl
CIBJO
South Sea Cultured Pearl
Gem-A
South Sea Cultured Pearl (not yet checked by this site — the entry's own English name is shown)
GSJ (Japan) formal name
南洋養殖真珠
GB/T naming counterpart (this name is not in the standard)
海水养殖珍珠 (GB/T 16552—2017 Table A.3, row “Saltwater Cultured Pearl”)
Mineralogical name
Cultured pearl from the Pinctada maxima oyster; primarily white, silver or golden
Trade names and synonyms
Not to be used as a name: South Sea pearl (market name)

Four-language names

简体中文
南洋养殖珍珠
繁體中文
南洋養殖珍珠
English
South Sea Cultured Pearl
日本語
南洋養殖真珠

National and regional formal names

Germany (RAL)
Südsee-Zuchtperle
European Union
South Sea Cultured Pearl (EU: "Zuchtperle" = cultured)

Qualifiers stripped from the headline name

  • FTC: (§23.19: definition; §23.21: "cultured" may not be dropped)
  • CIBJO: (CIBJO Pearl Book: cultured not "natural")

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
Cultured formation; treatments recorded separately

Treatments listed by standards

South Sea Cultured Pearl is not a material registered separately in GB/T 16552—2017 Annex B, Table B.1: the Cultured Pearl (Pearl) entry of Table B.1 lists bleaching as optimization and dyeing and irradiation as treatment, and this site applies the Cultured Pearl (Pearl) entry to South Sea Cultured Pearl. The full entry, including the effect column, is on the Cultured Pearl page; the notes to Table B.1 and the definitions of each treatment grade are on the Gem treatments page.

GB/T 16552-2017, Annex B, Table B.1

Under the “Cultured Pearl (Pearl)” row of Table B.1: Bleaching Optimization; Dyeing Treatment; Irradiation Treatment. The full row, with the effect column, is on the Cultured Pearl 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.

What it is and how it's identified

South Sea Cultured Pearl is registered as a cultured pearl (5.50) from Pinctada maxima (9.60); the registration notes that this is a CIBJO trade definition from an institutional handbook, not a national standard. The structure is registered for cultured pearls (the whole class): the inorganic part is a radially arranged aggregate, with aragonite orthorhombic and calcite trigonal, and the organic part is amorphous. Durability is registered for cultured pearls (the whole class): Mohs hardness 2.5–4, with cleavage usually not seen in the aggregate; when untreated, it effervesces on contact with acid. Density is registered for saltwater cultured pearls (the whole class) as 2.72–2.78 g/cm³. Optics are registered for cultured pearls (the whole class): the optic character is that of an aggregate, birefringence cannot be measured on the aggregate, and refractive index is 1.53–1.68; the registration notes that the refractive index is a spot-method reading, a typical value rather than an absolute limit, and that the clause has further sub-grades, with the overall value registered. Registered for cultured pearls (the whole class), the quality factor (lustre) when untreated is pearly.

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”.

Luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for cultured pearl (the whole class), so they are not repeated on the South Sea Cultured Pearl page; see the material facts on the Cultured Pearl entry.

Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of South Sea Cultured Pearl (how to read class-level values).

Definition

South Sea Cultured Pearl: a cultured pearl (5.50) from a Pinctada maxima (9.60). Extensively cultured in areas of the Indian and Pacific Oceans, including Myanmar, Indonesia, Philippines, and Northern Australia.

CIBJO Pearl Book 2024

Qualification

CIBJO trade definition from an institutional manual, not a national standard. The English text quotes the full definition at §5.186 of the Pearl Book 2024.

Source & check 2026-09-25
Source
  • CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §5.186, p.44 (locator checked 2026-09-25)
Fact checked on
2026-09-25

Structure

South Sea Cultured Pearl — structure (overall): inorganic part: aragonite (orthorhombic) and calcite (trigonal) in radiating aggregates; organic part: amorphous.

GB/T 16553—2017

Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

Durability

South Sea Cultured Pearl — Mohs hardness: 2.5–4

GB/T 16553—2017

123456789102.5–4References (diamond = value, bar = range; below)

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))

Mohs hardnessSource: GB/T 16553—2017
Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — cleavage: generally not seen on an aggregate

GB/T 16553—2017

Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — stability: effervesces in acid

GB/T 16553—2017

Treatment state
untreated
Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

Physical properties

South Sea Cultured Pearl — density: 2.72–2.78 g/cm³

GB/T 16553—2017

0.51.52.53.54.55.56.57.52.72–2.78
Specific gravitySource: GB/T 16553—2017
Does this standard apply
applies to this entry
What this covers
saltwater cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 Density · Saltwater cultured pearl (locator checked 2026-09-28)
Fact checked on
2026-09-26

South Sea Cultured Pearl — feel (texture): feels gritty when two surfaces are rubbed together

GB/T 16553—2017

Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

Optical

South Sea Cultured Pearl — optic character: aggregate

GB/T 16553—2017

Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — refractive index: 1.53–1.68

GB/T 16553—2017

1.31.72.12.52.93.31.53–1.68
Refractive indexSource: GB/T 16553—2017
Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
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 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — birefringence: not measurable on an aggregate

GB/T 16553—2017

Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

South Sea Cultured Pearl — pleochroism: not measurable on an aggregate

GB/T 16553—2017

Treatment state
untreated
Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (locator checked 2026-09-26)
Fact checked on
2026-09-26

Quality factors

South Sea Cultured Pearl — quality factor (lustre): pearly

GB/T 16553—2017

Treatment state
untreated
Does this standard apply
applies to this entry
What this covers
cultured pearl (the whole class)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.3.2 (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.

1.581.61.622.62.72.82.93Refractive indexSpecific gravity12345South Sea Cultured Pearl

This material (RI / SG midpoints): 1.605 / 2.75; Closest values: 1Larimar 1.62 / 2.82, 2Natural Conch Pearl / Natural Melo Pearl 1.595 / 2.84, 3Aquamarine 1.58 / 2.79, 4Turquoise 1.63 / 2.65, 5Prehnite 1.625 / 2.88

Show the full chart (330 registered materials)1.41.51.61.71.81.922.12.22.32.41234567Refractive indexSpecific gravity12345South Sea Cultured Pearl

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

Refractive index × specific gravity (all registered materials)Each dot is one material's registered refractive index and specific gravity (range midpoints, not measurements); gold = this material, dark = the nearest few (picked on this site by distance in RI ÷ 0.02 and SG ÷ 0.1, leaving out near-identical varieties of the same species)Source: each material's registered refractive index and specific gravity facts (GB/T 16553 and others; sources on each entry)

Related CIBJO terms

Dobo pearls

a commercial name for cultured pearls traded and exported through Dobo in Indonesia usually from Pinctada maxima.

CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §5.62, p.28

South-sea

an area of the Pacific and the Indian Oceans between Myanmar and Northern Australia and inclusive of Indonesia and the Philippines, the habitat of the Pinctada maxima (9.60) pearl oyster.

CIBJO Blue Book — Pearl Book (Pearl Commission 2024-1) (CIBJO): §5.185, p.44

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): §9.10 Australian south-sea pearl oyster · §9.26 Gold-lipped pearl oyster · §9.60 Pinctada maxima · §9.78 Silver-lipped pearl oyster

Testing and market

The CIBJO laboratory protocol covers South Sea Cultured Pearl under “Pearl” (§6.2.19): see identification on the Pearl entry; the required tests are listed on the CIBJO laboratory protocol table for Pearl.

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

16 CFR Part 23
Naming rule §23.21(g) · Source
16 CFR Part 23
Naming rule §23.20(b) · Source

Sources

Further reading

Related pages

Treatments recorded for this material

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 (South Sea Cultured Pearl) is marked.

This table scrolls sideways on narrow screens.

PageContentStatus
Browsing familyPearl and molluscan shell materialsLive
Treatments recorded for this materialBleached (via parent material), Dyed (via parent material), Irradiated (via parent material)Live
Related articlesTo be added (placeholder)Planned

Who maintains this page

The material facts in the South Sea Cultured 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. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.

Facts editor
June
Reviewer
Ralph
How facts are checked
Each fact is matched to the clause it cites; facts checked between 2026-09-25 and 2026-09-26
Last revised
2026-10-12
Purpose
Lets buyers and sellers check naming, disclosure and material facts clause by clause.

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