On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Commercial / trade name · Natural identity; treatment status unknown
Taishan Yu
A quartzose jade trade name in GB/T 34098-2017 Annex A Table A.1, grouped in one merged cell with other trade names and not matched to any single basic name (quartzose jade, quartzite jade, chalcedony, agate or jasper). It contains the place name Taishan; GB/T 34098 does not say whether this implies origin.
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 Taishan Yu forms and what gives its colourFormation setting, process and timescale; where its colour and optical effects come from, each finding graded and sourced
- Hardness, density and refractive index of Taishan YuEach value with its source and check date
- Taishan Yu 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 Taishan YuThe 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
Taishan Yu is a locality-based trade name for quartzose jade from Taishan, Guangdong; its parent material is quartz/chalcedony (SiO2). Chalcedony (cryptocrystalline quartz) commonly shows a granular aggregate structure with subtle banding, and a colorant mineral phase may occur along grain boundaries between coarser quartz grains, concentrating color in bands; quartz can also trap various fluid inclusions (petroleum, methane, water), recording fluids captured during crystallization. A quartzose jade body is built from such siliceous precipitation and aggregation, which the name alone cannot establish.
Scope: Applies to the origin of the underlying material of the quartzose jade (quartz / chalcedony) referred to by the origin trade name 'Taishan Yu'; does not constitute an identification conclusion for a specific sample or locality.
Sources G&G Winter 2015 · G&G Spring 2023 · GIA Jade Description
Where it forms
An environment of cryptocrystalline quartz (chalcedony) aggregation and precipitation, where quartz can trap fluid inclusions during crystallization
Sources G&G Winter 2015 · G&G Spring 2023
How it forms, step by step
Silica-rich fluids precipitate, forming granular aggregates of cryptocrystalline quartz (chalcedony).
Sources G&G Winter 2015
A colorant mineral phase may be distributed between grains, concentrating color in bands.
Sources G&G Winter 2015
During crystallization, quartz can trap fluid inclusions such as petroleum, methane, and water.
Sources G&G Winter 2015
Link to appearance
The granular aggregate structure and subtle banding come from cryptocrystalline quartz precipitation; color can arise from intergranular colorant phases or trace elements, and fluid inclusions may be visible in the quartz, not from the name.
Sources G&G Winter 2015 · GIA Jade Description
Timescale
The sources give no absolute age for Taishan Yu or its parent material.
Sources G&G Winter 2015 · G&G Spring 2023 · GIA Jade Description
Related base materials
- Quartzose jade (quartz/chalcedony): Taishan yu is a trade name for quartzose jade named after its origin (Taishan, Guangdong); the underlying material is quartz/chalcedony (SiO2), not an independent mineral species.
Supporting findings
Chalcedony (cryptocrystalline quartz) commonly shows a granular aggregate structure with subtle banding, and color may concentrate along grain boundaries between coarser quartz grains.
Evidence grade AScope: Generic structural feature of the parent material (quartz/chalcedony); not unique to the name Taishan Yu.
Sources G&G Winter 2015
During crystallization, quartz can trap various fluid inclusions (petroleum, methane, water), recording fluids captured at formation.
Evidence grade AScope: A generic phenomenon of fluid inclusions in quartz; does not mean any Taishan Yu specimen contains such inclusions.
Recorded localities
Authoritative sources name a single or principal locality.
Asia
- Beidou Town, Taishan, Jiangmen, Guangdong, ChinaDefined by a peer-reviewed paper as produced in Beidou Town
Sources Spectroscopy and Spectral Analysis (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 the origin determination guide and the overview of recorded localities.
Causes of colour and optical effects
Color in quartz/chalcedony can come from contained trace elements (such as chromium and nickel) or intergranular mineral phases.
Evidence grade AScope: States one possible color source in quartz/chalcedony; does not assert the specific coloring elements of any Taishan Yu specimen.
Sources G&G Winter 2015
Other research findings
Taishan Yu is a locality/trade name and does not constitute an independent mineral or material identity; the word 'jade' has historically been misapplied to many jade-like materials.
Evidence grade BScope: Distinguishes the name from material identity; not specimen identification or provenance.
Sources GIA Jade Description
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- GB/T 34098-2017 and GB/T 16552-2017 are recommended (non-mandatory) national standards whose full text is not freely obtainable; the official free preview does not cover them. This record could not verify their clause text, so it makes no assertion about the specific classification, entry, or table position of this locality trade name in those standards.
- The sources give no absolute age for Taishan Yu or its parent material.
- The structure, color, and fluid inclusions of quartz/chalcedony are generic parent-material facts; the sources do not attest a Taishan Yu locality or specimen specifically.
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
- Quartzose jade (trade name: Taishan Yu)
GB/T 34098—2017 Table A.1, §6 b) · CIBJO Gemstone Book 2022 4.2.3.3
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
"Taishan Yu" is a market name rather than a mineral species name; before using it, verify: Trade name rather than a mineralogical species name. Actual material is unverified.
What this means for you
Before buying, check the recommended listing name "Quartzose jade (trade name: Taishan Yu)" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- This entry's exact material identity is not fully settled.
- See “Disclosure and cautions” above
- Last reviewed
- 2026-09-26
Trade-name ruling
- Trade name rather than a mineralogical species name.
- Actual material is unverified.
- Suggested listing name
- Quartzose jade (trade name: Taishan Yu)
VerifyNames, standards, technical facts, clauses and sources
Names
Trade and mineralogical namesTaishan Yu is a commercial/trade name; GB/T 34098—2017 Table A.1 lists it as a quartz jade trade name, and the original does not say which basic name it corresponds to among quartzite jade, chalcedony, agate and jasper, so the basic name must first be established by testing; a trade name is not used on its own but together with the basic name, with the note “trade name: Taishan Yu” added in quality documents. Recommended listing nameThe suggested listing name is quartz jade (trade name: Taishan Yu). Names in four languagesThe language versions of the name are Simplified Chinese, Traditional Chinese, English (Taishan Yu) and Japanese (to be checked). Trade and mineralogical namesThe mineralogical name recorded in GB/T 34098 Table A.1 means quartz jade sold under the trade name Taishan Yu. Institution usageOn authority wording, the comparison across GIA, FTC, CIBJO and Gem-A shows the entry's own English name, Taishan Yu; the FTC and CIBJO texts have no wording for this name (checked); GIA and Gem-A are unchecked, and what is shown for bodies without a record does not represent their position. Japanese namesThe GSJ (Japan) wording for the entry's own Japanese name is not yet verified by this site.
- GSJ (Japan) formal name
- 台山玉（待核） (not yet checked for this body — the entry's own Japanese name is shown)
- Trade name listed in the GB/T standard (not used on its own)
- 台山玉 (GB/T 34098—2017 Table A.1; basic name not specified in the original — identify the material first)
- Mineralogical name
- Quartzose jade sold under the trade name Taishan Yu (GB/T 34098 Table A.1)
Four-language names
- 简体中文
- 台山玉
- 繁體中文
- 台山玉
- English
- Taishan Yu
- 日本語
- 台山玉（待核）
GB/T 34098 trade names
- Position in Table A.1
- 台山玉 Taishan Yu sits in the cell shared by quartzite jade, chalcedony, agate and jasper; the original does not say which one
- How to name it
- The original gives no basic name: identify the material first, then add the note “trade name: 台山玉 Taishan Yu”
The full table and naming rule are on the Quartzose Jade page.
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Quartz and chalcedony materials
- Identity tier
- Commercial / trade name
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
Among the registered material facts for Taishan Yu, Mohs hardness, density and refractive index all come from GB/T 34098—2017, and the cited clause gives them for quartzose jade (the whole class); they are not data measured on Taishan Yu on its own. Mohs hardness registered for quartzose jade (the whole class) is 6–7, and GB/T 34098—2017 also notes that Mohs hardness is sometimes below 6–7, as low as 5.5; this site notes that hardness alone does not amount to any advice on everyday wear. Density registered for quartzose jade (the whole class) is 2.53–2.72 g/cm³, and GB/T 34098—2017 also notes that density sometimes falls outside 2.53–2.72 g/cm³, as low as 2.48 g/cm³ and as high as 2.95 g/cm³; this site notes that what is registered is the main range and cannot be used as a threshold for deciding a material's identity. Refractive index registered for quartzose jade (the whole class) is 1.53–1.55. Chemical composition features are likewise given in the cited clause for quartzose jade (the whole class) and are not repeated on the Taishan Yu entry; see the material facts on the Quartzose Jade entry.
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: these whole-class features are given in the cited clause for quartzose jade (the whole class), so they are not repeated on the Taishan Yu page; see the material facts on the Quartzose Jade entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Taishan Yu (how to read class-level values).
Durability
Taishan Yu — Mohs hardness: 6–7
GB/T 34098—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
- quartzose jade (the whole class)
- Qualification
GB/T 34098-2017 §3.1 notes that hardness may sometimes fall to 5.5. Hardness alone does not support any everyday-wear advice.
Source & check 2026-09-26
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §3.1 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Taishan Yu — density: 2.53–2.72 g/cm³
GB/T 34098—2017
- Does this standard apply
- applies to this entry
- What this covers
- quartzose jade (the whole class)
- Qualification
GB/T 34098-2017 §3.1 notes that values may sometimes fall to 2.48 or rise to 2.95 g/cm³. The registered range is the main range, not a cut-off for identifying the material.
Source & check 2026-09-26
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §3.1 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Taishan Yu — refractive index: 1.53–1.55
GB/T 34098—2017
- Does this standard apply
- applies to this entry
- What this covers
- quartzose jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §3.1 (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.
This material (RI / SG midpoints): 1.54 / 2.62; Closest values: 1Charoite 1.554 / 2.66, 2Changhua Stone 1.56 / 2.6, 3Balin Stone 1.56 / 2.55, 4Shoushan Stone 1.56 / 2.7, 5Bamboo Coral 1.57 / 2.65
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
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.
- AQSIQ / SAC (China). GB/T 34098—2017 Quartzose jade — Classification and nomenclature.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- eCFR (United States). 16 CFR Part 23 — Guides for the Jewelry, Precious Metals, and Pewter Industries.
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
Related-entry tree for Quartz on this site: 74 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Taishan Yu) is marked.
- Quartz
Sub-entries (57)
- Agate
Sub-entries (1)
- Amethyst
- Ametrine
- Aventurine Quartz
- Aventurine Quartz / Green Aventurine
- Banded Agate
- Black Agate
- Bloodstone / Heliotrope
- Blue Lace Agate
- Carnelian
- Chalcedony
Sub-entries (2)
- Chrysoprase
- Citrine
- Clear Quartz / Rock Crystal
- Coated Quartz
- Colourless to White Quartz (brand name: Azeztulite)
- Crazy Lace Agate
- Dendritic Agate
- Dyed Agate (Treated: dyed)
- Elestial Quartz / Skeletal Quartz
- Eye Agate
- Flower Agate / Cherry Blossom Agate
- Green Quartz
- High-clarity quartz with golden needle-like inclusions
- Included Quartz
- Jasper
Sub-entries (1)
- Madeira Citrine
- Malachite Agate
- Morion / very dark Smoky Quartz
- Moss Agate
- Moss Chalcedony
- Multi-inclusion Quartz
- Onyx (banded chalcedony)
- Phantom Quartz
- Prase
- Prasiolite / Green Quartz
- Quartz Cat’s-eye
- Quartz claimed to be from the Himalayas
- Quartz Crystal
- Quartz with dark needle-like inclusions
- Quartz with fine fibrous inclusions
- Quartz with flower-like inclusions
- Quartz with golden needle-like inclusions
- Quartz with green needle-like inclusions
- Quartzite Jade
- Quartzose Jade
Sub-entries (9)
- Red Agate
- Rock Crystal
- Rose Quartz
- Rutilated Quartz
- Sard
- Sardonyx
- Silicified Asbestos
Sub-entries (2)
- Hawk’s Eye
- Tiger’s Eye
Sub-entries (1)
- Smoky Quartz
- Smoky Quartz (brown variety)
- Strawberry Quartz
- Yellow-green Quartz
- Agate
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Quartz and chalcedony materials | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Taishan Yu 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.