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Unspecified-material term · Trade name: material identity unverified · Actual material to be verified
Yanyuan Agate
A Chinese origin-based trade name for agate, not directly listed in the authoritative texts consulted; both the material and the Yanyuan origin still need evidence. 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 Yanyuan Agate 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 Yanyuan AgateIdentification points from the research literature; how far lab testing can go
- Treatments and enhancements of Yanyuan AgateThe enhancements and treatments the GB/T and JJA/AGL tables list
- Yanyuan Agate 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 Yanyuan AgateThe 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
Yanyuan Agate (Chinese trade/origin name; material unverified) is a trade name used in the Chinese market for a quartz-based ('quartz jade')/agate material, also called Yanyuan agate; it is not a mineral species. The substance it denotes is agate, which belongs to the microcrystalline forms of silica and is usually described as banded chalcedony while also carrying several other silica polymorphs - that is, cryptocrystalline quartz (chalcedony/agate). According to the leading hypothesis, the voids inside volcanic rock fill up cyclically, starting at the rim and working toward the middle, as silica-rich fluids pass in through microfissures or infiltration canals; how wide the zones are and what overall pattern results depends on the silica concentration of the fluids together with the temperature, the pressure and when those fluid pulses arrived, whereas Fe, Ti, Mn and other elements influence only the colour of the zones. Agate may be treated - quench-crackled and dyed, for instance - to alter its colour. Note: no definition of the name "Yanyuan Agate (Chinese trade/origin name; material unverified)" was found in the authoritative sources consulted (GIA, CIBJO); the name carries both origin and trade connotations, and both the material and the geographic origin require evidence.
Scope: Applies to the naming boundary of Yanyuan agate as a Chinese-market trade name for quartzose jade / agate, and an overview of the formation, composition and treatment of agate; an authoritative definition of the name itself is lacking in the cited sources (flagged as a grade C gap).
Sources G&G Fall 2013 · CIBJO Gemstone Book 2022 · G&G Summer 2020
Where it forms
Voids/geodes in volcanic rock — a setting where silica-rich fluids fill from the rim to the centre in cycles.
Sources G&G Fall 2013
Agate can occur as lens-shaped or spherical geodes within volcanic rocks such as Triassic basaltoids.
Sources G&G Fall 2013
How it forms, step by step
Silica-rich fluids enter voids in volcanic rock through microfissures or infiltration canals.
Filling proceeds from the rim to the centre in cycles, forming banded chalcedony/silica polymorphs.
Fe, Ti, Mn and other elements colour the zones differently; the material may be further treated, e.g. dyed.
Link to appearance
Agate is characterised by banded silica (chalcedony); the colour of the zones is governed by Fe, Ti, Mn and other elements, while the pattern reflects the filling cycles and fluid conditions.
Sources G&G Fall 2013 · CIBJO Gemstone Book 2022
Timescale
The source gives no absolute timescale for agate formation (though it notes crystallization can last millions of years and proceed in stages).
Sources G&G Fall 2013 · CIBJO Gemstone Book 2022 · G&G Summer 2020
Related base materials
- Chalcedony / agate (cryptocrystalline quartz): The quartzose jade/agate material referred to by this name, composed mainly of cryptocrystalline quartz
Supporting findings
According to the leading hypothesis, the voids inside volcanic rock fill up cyclically, starting at the rim and working toward the middle, as silica-rich fluids pass in through microfissures or infiltration canals; how wide the zones are and what overall pattern results depends on the silica concentration of the fluids together with the temperature, the pressure and when those fluid pulses arrived.
Evidence grade AScope: A hypothesis for banded-chalcedony formation.
Agate can occur as lens-shaped or spherical geodes within volcanic rocks (e.g. Triassic basaltoids).
Evidence grade AScope: A setting example; not locality-specific.
Recorded localities
Authoritative sources name a single or principal locality.
Asia
- Yanyuan County, Liangshan, Sichuan, ChinaBy definition the name refers to purple-green agate from Yanyuan; similar agate also comes from Luonan County, Shaanxi, but is not called Yanyuan agate
Sources Mineralogy and Petrology (Xia et al., 2020)
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
In the fluids, Fe, Ti and Mn and similar elements alter only the colour of the agate's zones.
Evidence grade AScope: A colour-cause statement.
How it is identified
The colour and inclusion appearance of Yanyuan agate cannot establish whether a stone is natural, synthetic or treated: quartz varieties that look alike may differ entirely in composition, growth history and treatment, and synthetic and natural quartz share essentially the same composition and physical properties, so the unaided eye cannot separate them. Laboratory identification rests on measurable properties and the division of labour between instruments — a polariscope with a conoscope lens can judge colour-zoning orientation from extinction and optic-axis readings, a refractometer gives refractive-index values, and EDXRF with infrared spectroscopy supplies chemical and structural fingerprints. Limitations: some methods depend on how the stone was cut and on comparison with reference material, and the final 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 G&G Summer 2014 · CIBJO Gemstone Book 2022
Other research findings
"Yanyuan Agate (Chinese trade/origin name; material unverified)" is a Chinese-market trade name for a quartz-based / agate material and is not a mineral species; the material and origin require identification and its basic name must be determined by testing as chalcedony/agate. The authoritative sources consulted (GIA, CIBJO) do not define the name, so it has no authoritative mineralogical definition and does not constitute an identifiable material type.
Evidence grade CScope: Based only on the cited authoritative sources; where they are silent the gap is stated, not filled from commercial sites.
Sources CIBJO Gemstone Book 2022
Agate belongs to the microcrystalline forms of silica and is usually described as banded chalcedony, though it also carries several other silica polymorphs; its principal component is cryptocrystalline quartz (chalcedony/agate).
Evidence grade AScope: Composition/structure of agate.
Sources G&G Fall 2013 · CIBJO Gemstone Book 2022
Chalcedony/agate can be treated, e.g. quench-crackled and dyed, to change colour; the actual treatment status of Yanyuan Agate (Chinese trade/origin name; material unverified) requires identification.
Evidence grade AScope: A generally available treatment for chalcedony/agate; it does not mean the material is necessarily treated.
Limits of this research
- Research status: No authoritative source specific to this material was found; findings come from the parent material or are marked as gaps
- The name does not appear in the authoritative sources consulted, so the name itself rests on evidence level C only; this account draws on general sources on agate/chalcedony, not on commercial gem shops or content farms.
- The name is an origin-plus-trade name; both the material and geographic origin require evidence.
- No absolute age for agate formation is given by the sources.
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
- Yanyuan Agate (use only once both material and origin are evidenced)
GB/T 16552—2017 5.1.1 c), 5.1.2.1 b)
Construction or treatment status
Actual material to be verified
Treatments recorded for this material: Heated / Heat-treated (via parent material), Filled / Fracture-filled (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
"Yanyuan Agate (Chinese trade/origin name; material unverified)" is a market name rather than a mineral species name; before using it, verify: Trade name rather than a mineralogical species name.
What this means for you
Before buying, check the recommended listing name "Yanyuan Agate (use only once both material and origin are evidenced)" 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
- Trade name rather than a mineralogical species name.
- Suggested listing name
- Yanyuan Agate (use only once both material and origin are evidenced)
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 |
|---|---|---|---|---|---|
| Heating | — | — | Optimization | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Dyeing | — | — | Optimization | — | — |
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Chalcedony)
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
Besides Yanyuan Agate, the name register records "Yanyuan agate", for which no restriction on use as a name is recorded; 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).
Standard and listing namesThe name Yanyuan Agate is not listed in GB/T 16552—2017, and the basic name must be established by testing; the mineralogical name describes a Chinese agate-type trade and origin term, and the actual material and origin require evidence. On the market it is also called Yanyuan coloured agate and Yanyuan agate, Yanyuan agate being an English transliteration. The suggested listing name is Yanyuan Agate (to be used once there is evidence of both material and origin). Names in four languagesNames are registered in four languages: Simplified Chinese, Traditional Chinese, English (Yanyuan Agate) and Japanese. Institution usageOn authority wording, the FTC and CIBJO texts on file have no wording for this name (checked), and the wording of GIA and Gem-A is unchecked; Yanyuan Agate is the entry's own English name and does not represent the position of GIA, FTC, CIBJO or Gem-A. The qualifying note separated from the title name, “Chinese trade or origin name, material unverified”, comes from the entry's own English name. Japanese namesThe entry's own Japanese name is shown for the GSJ (Japan) formal name, and the wording used by the GSJ for this name is not yet verified by this site.
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.
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| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (2) | ||||
| Yanyuan agateEnglish | transliteration | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| 盐源彩色玛瑙Simplified Chinese | 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
- 塩源瑪瑙（中国市場・産地名・材質未同定） (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)
- basic name to be determined by testing (GB/T 16552—2017 §5.1.2.1 b))
- Mineralogical name
- Chinese agate-related trade and origin term; actual material and geographic origin require evidence
Four-language names
- 简体中文
- 盐源玛瑙
- 繁體中文
- 鹽源瑪瑙
- English
- Yanyuan Agate (Chinese trade/origin name; material unverified)
- 日本語
- 塩源瑪瑙（中国市場・産地名・材質未同定）
Qualifiers stripped from the headline name
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Material identity unspecified
- Material domain
- Unspecified-material term
- Browsing family
- Bead-form and unidentified trade terms
- Identity tier
- Trade name: material identity unverified
- Mineral chemical class
- Mixed / composition-dependent
- Construction or treatment status
- Actual material to be verified
Treatments listed by standards
Yanyuan Agate is not listed separately in GB/T 16552—2017, Annex B, Table B.1; this site applies the “Chalcedony (Agate/Jasper)” row of Table B.1 to Yanyuan Agate: heating is listed as an optimization, dyeing as an optimization, and filling is graded. How filling is graded and what Table B.1 is are on this site's Gem treatments page, and the full row, with the effect column, is on the Chalcedony entry.
GB/T 16552-2017, Annex B, Table B.1
Under the “Chalcedony (Agate/Jasper)” row of Table B.1: Heating Optimization; Filling Graded — see §5.4.1, Table 1; Dyeing Optimization. The full row, with the effect column, is on the Chalcedony 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
Yanyuan Agate is the market name for purple-green agate from Yanyuan, Sichuan, also called Yanyuan colourful jade; purple-green agate takes purplish red and pea green as its main colours, has no distinct banding or pattern, and is a multicoloured agate. The classification proposed by the journal paper's authors, paraphrased here, is not a national standard; the authors consider that Yanyuan Agate carries a place-of-origin connotation and is unsuitable as a variety name for classification, and propose that it be called purple-green agate together with similar material from Luonan, Shaanxi. The paper's citations for the definition and composition both refer to another 2017 study of Yanyuan Agate, a conference paper whose original this site could not obtain. The composition described in the paper is limited to purple-green agate from Yanyuan: the main mineral is quartz, with small amounts of haematite, lepidocrocite, anatase, calcite and others; the paper also states that the purplish red of Yanyuan Agate is caused by iron and titanium, and the green mainly by copper. What any particular piece sold under the name Yanyuan Agate actually is must still be established by testing.
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
Stone sold as Yanyuan Agate: the market name for purple-green agate from Yanyuan, Sichuan; purple-green agate is a multicoloured agate whose main colours are purplish red and pea green, with no distinct banding or pattern.
Mineralogy and Petrology (Xia et al., 2020)
- Qualification
This is the classification proposed by the authors of a journal paper (paraphrased here), not a national standard. The authors consider the name too tied to one place to serve as a variety name and group the material with similar agate from Luonan, Shaanxi, as purple-green agate.
This passage of the paper ends with a citation to an earlier 2017 study of Yanyuan agate (a conference paper we could not obtain).
Source & check 2026-09-29
- Source
- Xia et al., “Gemological Classification and Identification Characteristics of Agate”, Mineralogy and Petrology 40(2) (2020): §2.2.1.1 Purple-green agate; Table 1 (multicoloured agate row), p. 5 (locator checked 2026-09-29)
- Fact checked on
- 2026-09-29
Stone sold as Yanyuan Agate — composition (phase): mainly quartz, with small amounts of hematite, feroxyhyte, anatase, calcite and other minerals.
Mineralogy and Petrology (Xia et al., 2020)
- Qualification
This passage of the paper ends with a citation to an earlier 2017 study of Yanyuan agate (a conference paper we could not obtain). It concerns purple-green agate from Yanyuan; the paper adds that the purplish red comes from iron and titanium and the green mainly from copper.
What a given piece sold under this name is made of still has to be tested.
Source & check 2026-09-29
- Source
- Xia et al., “Gemological Classification and Identification Characteristics of Agate”, Mineralogy and Petrology 40(2) (2020): §2.2.1.1 Purple-green agate, p. 5 (locator checked 2026-09-29)
- Fact checked on
- 2026-09-29
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Testing and market
Among the identification leads for Yanyuan Agate: imitations sold as “new-mine Yanyuan Agate” are in fact a mixture of barite, calcite and epoxy resin; standard gemmological tests can separate these imitations from Yanyuan Agate: density above 2.70 g/cm³, easily scratched with a knife, and effervescence with a drop of hydrochloric acid. The researchers suggest that imitations sold as “new-mine Yanyuan Agate” be named “imitation agate” under the national standard; what they say applies only to imitations sold under that name, not to all goods sold as Yanyuan Agate. The leads come from Chen Yuwei et al., “Gemmological and Spectroscopic Characteristics of an Imitation of Yanyuan Agate”.
How far testing can go
Stone sold as Yanyuan Agate — how far testing can go (separation): an imitation sold as “new-mine Yanyuan agate” proved to be a mixture of barite, calcite and epoxy resin; routine tests tell it from Yanyuan agate: density above 2.70 g/cm³, easily scratched with a knife, and it fizzes with a drop of hydrochloric acid.
Journal of Gems & Gemmology (Chen et al., 2025)
- Treatment state
- any treatment state
- Qualification
The researchers recommend naming such material “agate imitation” under the national standard. This concerns this one imitation, not everything sold as Yanyuan agate.
Source & check 2026-09-29
- Source
- Chen et al., “Gemmological and Spectroscopic Characteristics of A Kind of Imitation of Agate from Yanyuan”, Journal of Gems & Gemmology 27(2) (2025): Section “Abstract” (locator checked 2026-09-29)
- Fact checked on
- 2026-09-29
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
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Bead-form and unidentified trade terms | Live |
| Treatments recorded for this material | Heated / Heat-treated (via parent material), Filled / Fracture-filled (via parent material), Dyed (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Yanyuan Agate 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.