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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral / gemstone variety · Natural identity; treatment status unknown
Tianhuang
Field-pit stone from the paddy fields of central Bantian, within Shoushan Stone. GB/T 16553-2017 §5.2.31.3 states that yellow, red, white and black colors are all called "Tianhuang", so it is not only yellow, nor is it all field-pit stone. 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 Tianhuang forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- Caring for and wearing TianhuangDurability indicators and wearing advice
- Hardness, density and refractive index of TianhuangEach value with its source and check date
- Tianhuang 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?
- Name origin and history of TianhuangWhere the name comes from
- Listing and disclosing TianhuangThe 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
Tianhuang is a variety name of Shoushan stone, referring to Shoushan stone from the Zhongban Tiankeng field; its composition varies by variety, the aggregate consisting mainly of dickite, kaolinite, nacrite, illite or pyrophyllite, so it is not a single mineral species. These clay minerals belong to the kaolinite-serpentine group and are largely products of hydrothermal alteration or weathering: they form along hydrothermal veins by alteration of aluminosilicate minerals, and also occur as an authigenic sedimentary mineral. Because the variety, locality and parent-mineral assemblage all require separate identification, this record gives only the formation mechanisms of the parent minerals in the available mineralogical sources, without presenting a parent mineral's general facts as exclusive to Tianhuang. GB/T 16553 is a nomenclature/identification standard whose full text is unavailable, and no clause numbers are relied on for the formation content.
Scope: Applies to explaining the main constituent minerals of Tianhuang as a variety of Shoushan stone and the formation mechanisms of those parent minerals; not applicable to determining a specific variety, locality, authenticity or value directly from the name.
Sources CIBJO Gemstone Book 2022 · RRUFF Dickite · RRUFF Kaolinite +1
Where it forms
Hydrothermal alteration setting: the clay minerals form along hydrothermal veins by alteration of aluminosilicate minerals.
Sources RRUFF Dickite · RRUFF Kaolinite · RRUFF Pyrophyllite
Supergene weathering and sedimentary setting: kaolinite replaces aluminosilicate minerals and can form as an authigenic sedimentary mineral.
Sources RRUFF Dickite · RRUFF Kaolinite · RRUFF Pyrophyllite
Pyrophyllite occurrence: hydrothermal veins and bedded deposits in schistose metamorphic rocks.
Sources RRUFF Dickite · RRUFF Kaolinite · RRUFF Pyrophyllite
How it forms, step by step
Aluminosilicate minerals are altered under hydrothermal or weathering conditions.
Sources RRUFF Dickite · RRUFF Kaolinite
The alteration system precipitates kaolinite-group clay minerals (dickite, kaolinite, nacrite, etc.).
Sources RRUFF Dickite · RRUFF Kaolinite
These clay minerals (possibly with pyrophyllite and illite) make up the Shoushan stone aggregate to which Tianhuang belongs.
Sources RRUFF Dickite · RRUFF Kaolinite
Link to appearance
It appears as a fine-grained carving stone that may be yellowish, but neither appearance nor name can substitute for identification of the variety and its parent minerals.
Sources CIBJO Gemstone Book 2022 · RRUFF Dickite · RRUFF Kaolinite
Timescale
The cited sources give no absolute age or growth duration for Tianhuang or its parent minerals.
Sources CIBJO Gemstone Book 2022 · RRUFF Dickite · RRUFF Kaolinite +1
Related base materials
- Dickite: One of the principal constituent minerals (mineral species)
- Kaolinite: One of the principal constituent minerals (mineral species)
- Pyrophyllite: Constituent mineral of some varieties (mineral species)
Supporting findings
Dickite and kaolinite form along hydrothermal veins by alteration of aluminosilicate minerals, and also occur as an authigenic sedimentary mineral.
Evidence grade BScope: Describes formation mechanisms of the kaolinite-group parent minerals; not exclusive to the name Tianhuang.
Sources RRUFF Dickite · RRUFF Kaolinite
Pyrophyllite is an uncommon mineral; it is found both in hydrothermal veins and as bedded deposits hosted in schistose metamorphic rocks, and it may be one of the constituents of certain Shoushan stones (the series that includes Tianhuang).
Evidence grade BScope: Occurrence of pyrophyllite; it does not confirm that any Tianhuang sample contains pyrophyllite.
Sources RRUFF Pyrophyllite
Recorded localities
Authoritative sources name a single or principal locality.
Asia
- Shoushan Creek paddy fields, Jin'an District, Fuzhou, Fujian, ChinaMainly from the Tianhuang creek and adjacent paddy fields of the Shoushan basin
Sources Natural Resources Science Popularization and Culture (2023)
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.
Where the name comes from
The origin of the stone name "tianhuang" itself is not given in the cited sources. The etymologies below belong to its constituent minerals: dickite honours the Scottish metallurgical chemist Allan Brugh Dick (1833-1926); kaolinite traces to a mangled version of the Chinese place-name Kauling, meaning 'high ridge'; pyrophyllite comes from Greek words for 'fire' and 'leaf', because when heated it flakes apart into fan-like forms. These etymologies belong to the constituent minerals, not to the name "tianhuang" itself.
Evidence grade BScope: The etymology explains only the origin of the name; it does not establish the material's composition, locality, naturalness, or treatment.
Sources RRUFF Dickite · RRUFF Kaolinite · RRUFF Pyrophyllite
Other research findings
Tianhuang is a variety name of Shoushan stone (a variety named under the Shoushan entry of GB/T 16553); its aggregate composition varies by variety (dickite, kaolinite, nacrite, illite or pyrophyllite), and it is not a single mineral species.
Evidence grade BScope: A naming/identity-boundary judgement; the full text of GB/T 16553 could not be obtained, so the conclusion that depends on it could not be checked against the standard and no clause of it is cited.
Sources CIBJO Gemstone Book 2022 · RRUFF Dickite
Dickite and kaolinite have the formula Al2Si2O5(OH)4; dickite, kaolinite, nacrite and halloysite are polymorphs of one another.
Evidence grade BScope: Composition and polymorphism of the parent minerals; does not assert the quantitative composition of any Tianhuang sample.
Sources RRUFF Dickite · RRUFF Kaolinite
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
- Tianhuang is a variety of Shoushan stone (a rock/aggregate), not a single mineral species; no quantitative assemblage of any variety is confirmed.
- The cited sources cover only the parent minerals; no authoritative source dedicated to Tianhuang has been found.
- The full text of GB/T 16553 could not be obtained, so no clause of it is cited and the conclusion that depends on it could not be checked against the standard.
- Not a judgement of authenticity, origin or value.
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
- Shoushan Stone (Tianhuang)
GB/T 16553—2017 §5.2.31.3
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
Tianhuang's material identity has open questions that are not fully settled; this site lists it as "Shoushan Stone (Tianhuang)" pending further verification.
Evidence
- GB/T · §5.2.31.3
What this means for you
Before buying, check the recommended listing name "Shoushan Stone (Tianhuang)" 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
Care and wear
No institutional care guidance is registered for this material yet; below are its durability indicators and general guidance.
Durability and wearing
Numbers in curly braces, such as {111}, are crystallographic face symbols (Miller indices): each marks a set of crystal faces or cleavage planes. They are reproduced as written in the cited source.
Toughness
Flexible but inelastic
Daily wear
Hardness of only 2–2.5 makes it very soft and easily scratched or abraded, and with one perfect {001} cleavage it splits under pressure or a knock; it is best used for seals, carvings or display rather than high-wear daily wear.
Care
No cleaning method is given in the source; dust with a soft cloth or wipe with a barely damp soft cloth, avoid soaking, ultrasonic/steam cleaning and acidic cleaners, and keep away from hard objects to prevent scratching.
General guidance: LumaLark's general guidance inferred from the material's properties (hardness, toughness, cleavage); not text from the cited source, and not a guarantee for any specific piece.
Scope: This field describes the material's general properties and is not a finished-product durability promise; it gives no warranty of any specific piece's durability or safety, and the durability of treated (filled, dyed, coated) or composite/assembled material must be assessed separately.
VerifyNames, standards, technical facts, clauses and sources
Names
The name register below lists one name for Tianhuang in a non-Latin script: 1 with no restriction recorded on use as a name.
Recommended listing nameThe Chinese formal name for Tianhuang comes from GB/T 16553—2017; the suggested listing name is Shoushan stone (Tianhuang). Candidate search termsThe trade name and synonym is Tiankeng stone, a market name used only as a candidate search term, with no restriction recorded on its use as a name; GB/T 16553—2017 calls Tiankeng stone of any colour from the fields of Zhongban Tianhuang, so Tiankeng stone covers a wider range than Tianhuang. Trade and mineralogical namesThe mineralogical name is Shoushan stone from the fields of Zhongban, an aggregate mainly of dickite, kaolinite, nacrite, illite or pyrophyllite. Names in four languagesThe four-language names cover Simplified Chinese, Traditional Chinese, English (Tianhuang) and Japanese (to be checked); the GSJ (Japan) wording for the entry's own Japanese name is not yet verified by this site. Institution usageThe FTC and CIBJO texts have no wording for Tianhuang (checked), and the wording of GIA and Gem-A is unchecked; Tianhuang is the entry's own English name and does not represent those bodies' position.
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) | ||||
| 田坑石Simplified Chinese | market name | search candidate only | no restriction recorded | GB/T 16553—2017 §5.2.31.3; Note: GB/T 16553—2017 §5.2.31.3 calls tiankeng stone of every colour from the Zhongban fields “tianhuang”; tiankeng stone is the wider term, so it is kept as a search candidate only. |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 田黄（待核） (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 田黄 (GB/T 16553—2017 §5.2.31.3)
- Mineralogical name
- Shoushan stone from the Tiankeng fields of Zhongban (GB/T 16553 §5.2.31.3); aggregate mainly of dickite, kaolinite, nacrite, illite or pyrophyllite
Four-language names
- 简体中文
- 田黄
- 繁體中文
- 田黃
- English
- Tianhuang
- 日本語
- 田黄（待核）
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Rocks and polymineral aggregates
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Mixed / composition-dependent
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The material facts for Tianhuang take the cited clause's values for Shoushan stone (the whole class); they are not data measured on Tianhuang on its own: Mohs hardness 2–3, density 2.5–2.9 g/cm³, refractive index 1.56, and body colour yellow, red, white or black, namely the tiankeng stone produced in the fields of Zhongbantian, with the body colour item carrying the treatment state untreated. The refractive index is the reading commonly obtained by the spot method, a typical value rather than an absolute limit; the cited clause calls all these colours from Zhongbantian Tianhuang, so Tianhuang does not mean yellow only. Chemical composition, luminescence, UV-visible spectrum, infrared spectrum and magnification are likewise given in the cited clause for Shoushan stone (the whole class) and are not repeated under Tianhuang; see the Shoushan Stone 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, luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for Shoushan stone (the whole class), so they are not repeated on the Tianhuang page; see the material facts on the Shoushan Stone entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Tianhuang (how to read class-level values).
Durability
Tianhuang — Mohs hardness: 2–3
GB/T 16553—2017
Reference points on this site: Talc 1–3, Fluorite 4, Apatite 5–5.5, Orthoclase 6–6.5, Topaz 8, Diamond 10 (Source: GB/T 16553—2017); Gypsum 1.5–2, Calcite 3, Quartz 7 (Source: Handbook of Mineralogy); Corundum 9 (Source: GIA Gem Encyclopedia (care guide))
- Does this standard apply
- applies to this entry
- What this covers
- Shoushan stone (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.31 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Tianhuang — density: 2.5–2.9 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- Shoushan stone (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.31 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Tianhuang — refractive index: 1.56
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- Shoushan stone (the whole class)
- Qualification
The clause we cite gives this as a value commonly read by the spot (distant-vision) method. It is a common value, not an absolute limit.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.31 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Tianhuang — body colour: yellow, red, white and black (Tiankeng stone from the Zhongban fields).
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- Qualification
Tianhuang is not only yellow: the clause we cite applies the name to stones of all these colours from the Zhongban fields.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.31 (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): 1.56 / 2.7; Closest values: 1Synthetic Beryl 1.57 / 2.69, 2Aventurine Quartz 1.548 / 2.67, 3Qingtian Stone 1.565 / 2.77, 4Iolite 1.563 / 2.61, 5Labradorite 1.54 / 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 16553—2017 Gems — Testing.
- 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 Shoushan Stone on this site: 2 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Tianhuang) is marked.
- Shoushan Stone
Sub-entries (1)
- Tianhuang
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Rocks and polymineral aggregates | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Tianhuang 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.