On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Trade name: colour / appearance variety · Natural identity; treatment status unknown
Silicified Asbestos
A cryptocrystalline to crystalline quartz aggregate formed when silica replaces asbestos fibers. Yellowish material may be called Tiger’s Eye, and bluish material may be called Hawk’s Eye. 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 Silicified Asbestos 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 Silicified AsbestosIdentification points from the research literature
- Treatments and enhancements of Silicified AsbestosThe enhancements and treatments the GB/T and JJA/AGL tables list
- Hardness, density and refractive index of Silicified AsbestosEach value with its source and check date
- Silicified Asbestos 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 Silicified AsbestosThe 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
Silicified asbestos (Chinese mubianshi) is a pseudomorph/replacement aggregate in which siliceous material has replaced crocidolite, the fibrous blue variety of the sodic amphibole riebeckite. Authority sources disagree on the mechanism: a long-held explanation is pseudomorphism, with quartz replacing crocidolite; another (Heaney and Fisher, 2003) proposes that quartz and riebeckite grew synchronously through an episodic crack-seal mechanism, as optical and electron microscopy found no evidence of pseudomorphism. The aggregate consists of columnar polycrystalline quartz with aligned amphibole needle inclusions; the primary blue comes from crocidolite, while the golden-brown (tiger's-eye) colour comes from iron-rich amphibole needles weathering to iron oxides. Its chatoyant band comes from selective reflection off the oriented fibrous inclusions. Health and safety: crocidolite is an asbestiform amphibole mineral; although the finished material is silicified, fibrous dust must be controlled when cutting/polishing rough, so this record is stated conservatively and flagged in limitations.
Scope: Covers fibrous cat's-eye aggregates formed by quartz-bearing material replacing or intergrown with crocidolite (riebeckite) fibres (the silicified asbestos/tiger's eye/hawk's eye group); does not cover quartz lacking such oriented fibres, and draws no quantitative conclusions on the safety of finished products.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Where it forms
Iron-rich siliceous settings hosting crocidolite (riebeckite) fibres, as described by the source.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Later near-surface weathering (oxidation) that converts amphibole needles to iron (hydr)oxides.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
How it forms, step by step
Crocidolite (the fibrous blue variety of riebeckite, an asbestiform asbestos mineral) forms in an iron-rich siliceous setting.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Quartz then either replaces crocidolite pseudomorphously or grows synchronously with riebeckite via an episodic crack-seal mechanism.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
This yields an aggregate of columnar polycrystalline quartz with aligned amphibole needle inclusions.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Iron-rich needles weather to iron oxides (golden-brown); light reflects selectively off the aligned fibres, producing chatoyancy.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Safety note: the finished material is silicified/replaced, but asbestos-fibre dust must be controlled when handling rough.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Link to appearance
The primary blue/blue-grey comes from crocidolite itself, and the golden-brown from iron-oxide-weathered amphibole needles; the cat's-eye band direction is set by the oriented fibrous inclusions, not the columnar quartz crystals.
Sources G&G Summer 2025
Timescale
The source gives no absolute timescale for the formation of silicified asbestos, only mechanism hypotheses.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Related base materials
- Quartz (SiO2): Replacing/intergrown mineral: silicified asbestos is an aggregate in which quartz material has replaced, or is intergrown with, fibrous amphibole
- Crocidolite (fibrous blue variety of the sodic amphibole riebeckite): The replaced fibrous parent; belongs to the asbestiform amphiboles
Supporting findings
Silicified asbestos forms either by quartz pseudomorphously replacing crocidolite or by synchronous crack-seal growth of quartz and riebeckite; the two hypotheses coexist and the mechanism is unsettled.
Evidence grade AScope: Two competing hypotheses; the source does not decide which applies and gives no absolute age.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Northern Cape, South AfricaGB/T 16552 groups it with silicified asbestos; localities are those recorded for tiger's eye and hawk's eye
Sources Mindat: Tiger's Eye
- Griqualand West, Northern Cape, South AfricaGB/T 16552 groups it with silicified asbestos; localities are those recorded for tiger's eye and hawk's eye
Sources Mindat: Hawk's Eye
Oceania
- Pilbara, Western Australia, AustraliaGB/T 16552 groups it with silicified asbestos; localities are those recorded for tiger's eye and hawk's eye
Sources GIA Tiger's-Eye Quartz
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
The chatoyancy of silicified asbestos is produced by selective reflection off aligned fibrous mineral inclusions, not by the columnar quartz crystals.
Evidence grade AScope: Concerns replacement quartz with oriented fibrous inclusions; cutting orientation affects the band.
How it is identified
Silicified asbestos (tiger's-eye) can look much like imitations, and neither colour nor sheen proves it is natural or untreated. Its major- and trace-element chemistry — the kind of data obtained by LA-ICP-MS or an electron microprobe — is what laboratory workers use to characterise such material and to check chemical consistency, while origin or treatment calls rest on reference databases and are never certain. Such measurements require a specialist laboratory, and the conclusion should be issued by a qualified body; a reader cannot identify a specimen from this entry.
Evidence grade AScope: A general principle for such material; chemical and origin judgements require a specialist laboratory and remain uncertain, and the conclusion should come from a qualified body.
Other research findings
Crocidolite is the fibrous blue variety of the sodic amphibole riebeckite and is an asbestiform asbestos mineral; silicified asbestos is the aggregate formed by quartz-rich material replacing/coexisting with it.
Evidence grade AScope: A mineral-identity statement; rough handling involves asbestos dust, with the safety note carried in limitations.
Overall, silicified asbestos is a fibrous chatoyant aggregate of quartz-rich material replacing/coexisting with crocidolite fibres: the primary blue comes from crocidolite, the golden-brown from iron-oxide-weathered amphibole needles, and the band from fibre orientation; the finished material is silicified, and asbestos dust must be controlled when processing rough.
Evidence grade BScope: A multi-source summary; fibre type and oxidation degree vary with locality and variety.
Sources G&G Summer 2025 · GIA Tiger's-Eye Quartz
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- Health and safety (high-risk; stated conservatively): the fibrous parent of silicified asbestos, crocidolite, is an asbestiform asbestos mineral. Although the finished material is silicified/replaced and typically no longer shows separable asbestos fibres, cutting, crushing and polishing the rough can generate asbestos-class fibre dust, which must be controlled to avoid inhalation as for asbestos materials. This record makes no quantitative safety claim about any finished product; occupational-health requirements follow local regulation and professional assessment.
- Two competing formation hypotheses (pseudomorphism vs crack-seal) remain unresolved in the source.
- The sources describe tiger's-eye/hawk's-eye/pietersite in English and provide no dedicated authority definition of the Chinese name mubianshi (silicified asbestos); equating the Chinese trade/standard name with the silicified-crocidolite material is an inference.
- The source provides no absolute geological age for the formation of silicified asbestos.
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
- Silicified Asbestos
GB/T 34098—2017 §5.5, Table A.1 · GB/T 16552—2017 Table A.2 “Silicified Jade(Silicified Asbestos/ Silicified Wood/ Silicified Coral)”
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Dyed, Filled / Fracture-filled
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
"Silicified Asbestos" is a market name rather than a mineral species name; before using it, verify: Industry-wide term that does not denote a single species.
What this means for you
Before buying, check the recommended listing name "Silicified Asbestos" 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
- Industry-wide term that does not denote a single species.
- Suggested listing name
- Silicified Asbestos
Care and wear
No care facts are recorded for this entry itself. Its parent material has care records: see Quartz.
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 |
|---|---|---|---|---|---|
| Dyeing | — | — | Treatment | — | — |
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Silicified Jade)
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
VerifyNames, standards, technical facts, clauses and sources
Names
The name register below lists one name for Silicified Asbestos in a non-Latin script: 1 with no restriction recorded on use as a name.
Standard and listing namesThe GB/T 16552—2017 formal name for Silicified Asbestos comes from the Silicified Jade row of Table A.2, a row that groups silicified wood, silicified coral and silicified asbestos; GB/T 34098—2017 Table A.1 lists the trade names tiger's-eye and hawk's-eye in the Silicified Asbestos row. The suggested listing name is Silicified Asbestos, and the synonym or trade name is a Chinese term for silicified asbestos. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Silicified Asbestos) and Japanese (with tiger's-eye and hawk's-eye in katakana); for Japan's GSJ, the entry has its own Japanese name, and the wording of Japan's GSJ for it is not yet verified by this site. Institution usageAmong GIA, FTC, CIBJO and Gem-A, the FTC and CIBJO texts on file have no wording for Silicified Asbestos (checked), and GIA and Gem-A are unchecked; bodies without a recorded wording show the English name Silicified Asbestos, which does not represent their position. Trade and mineralogical namesThe mineralogical name describes a cryptocrystalline to crystalline quartz aggregate replacing asbestos fibres.
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) | ||||
| 硅化石棉Simplified Chinese | synonym | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 珪化石綿（タイガーアイ／ホークスアイ） (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 木变石 (GB/T 16552—2017 Table A.2, row “Silicified Jade(Silicified Asbestos/ Silicified Wood/ Silicified Coral)”)
- Mineralogical name
- Cryptocrystalline-to-crystalline quartz aggregate replacing asbestos (crocidolite) fibres
Four-language names
- 简体中文
- 木变石
- 繁體中文
- 木變石
- English
- Silicified Asbestos
- 日本語
- 珪化石綿（タイガーアイ／ホークスアイ）
GB/T 34098 trade names
GB/T 34098-2017 Table A.1 lists on the silicified asbestos row: 虎睛石 Hujing Shi, 鹰睛石 Yingjing Shi, matching clause 5.5.
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
- Trade name: colour / appearance variety
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
For Silicified Asbestos, the Silicified Jade row (grouping silicified wood, silicified coral and silicified asbestos) of GB/T 16552—2017 Annex B, Table B.1 lists dyeing and filling as optimization and treatment methods. Dyeing improves or changes colour, category treatment; filling improves or changes durability and appearance, with its category given by the GB/T 16552—2017 grades. What Table B.1 is, and how the grades are defined, are on the Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Table B.1, row “Silicified Jade (Silicified Asbestos/Silicified Wood/Silicified Coral)” (p.16):
This table scrolls sideways on narrow screens.
| Method | Effect | Category |
|---|---|---|
| Dyeing | Improves or changes colour | Treatment |
| Filling | Improves or changes durability and appearance | Graded — see §5.4.1, Table 1 |
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
The chemical composition, luminescence, UV-visible spectrum, infrared spectrum and magnification of Silicified Asbestos are written for silicified jade as a whole class, not measured on Silicified Asbestos itself. Its structure is a quartz aggregate formed when asbestos fibres are replaced by silica, ranging from cryptocrystalline to phanerocrystalline and mostly fibrous. For silicified jade as a whole class: Mohs hardness 5–7, cleavage none, density 2.48–2.85 g/cm³, optic character anisotropic aggregate, refractive index 1.544–1.553 (this site notes that the cited clause has finer sub-ranges and the register takes the overall value), birefringence not measurable for an aggregate, and chatoyancy visible. Silicified Asbestos is also registered as commonly showing chatoyancy; untreated, polished surfaces usually have a silky or vitreous lustre and fracture surfaces a waxy lustre.
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 silicified jade (the whole class), so they are not repeated on the Silicified Asbestos page; see the material facts on the Silicified Jade entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Silicified Asbestos (how to read class-level values).
Structure
structure (overall)2 sources compared
Silicified Asbestos — structure (overall): crystalline aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — structure (overall): a cryptocrystalline to phanerocrystalline quartz aggregate formed where silica has replaced asbestos fibers. The texture is mainly fibrous.
GB/T 34098—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-17
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §5.5 (locator checked 2026-09-17)
- Fact checked on
- 2026-09-17
Durability
Silicified Asbestos — Mohs hardness: 5–7
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
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — cleavage: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Silicified Asbestos — density: 2.48–2.85 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Silicified Asbestos — optic character: anisotropic aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — refractive index: 1.544–1.553
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — birefringence: not measurable on an aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — pleochroism: not measurable on an aggregate
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
optical effect (chatoyancy)2 sources compared
Silicified Asbestos — optical effect (chatoyancy): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — optical effect (chatoyancy): Chatoyancy is commonly seen
GB/T 34098—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-17
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §5.5 (locator checked 2026-09-17)
- Fact checked on
- 2026-09-17
Silicified Asbestos — body colour: yellow, brownish yellow, brownish red, dark blue, greyish blue, greenish blue and other colours.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- Qualification
In chapter 5 of GB/T 16553—2017, the colour entries of Chrysoberyl, Quartzite Jade, Cat’s-eye and other variety clauses also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 Colour · Silicified asbestos (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Silicified Asbestos — common colours: golden yellow, brownish yellow, greyish blue, greenish blue and similar colours; silicified asbestos dominated by golden or brownish yellow tones may be called tiger's-eye, and silicified asbestos dominated by greyish or greenish blue tones may be called hawk's-eye.
GB/T 34098—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- Qualification
Among the quartzose jade varieties in GB/T 34098—2017, Quartzite Jade, Chalcedony, Agate and other varieties also name yellow or a yellowish colour among their common colours; the standard separates these varieties by crystallinity and by whether they show silica-replacement pseudomorphs.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §5.5 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
- CIBJO definitions
- chatoyancy
Quality factors
quality factor (lustre)2 sources compared
Silicified Asbestos — quality factor (lustre): vitreous; greasy or waxy on the fracture; silicified asbestos may also show a silky luster.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- silicified jade (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.6 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silicified Asbestos — quality factor (lustre): polished surfaces commonly silky or vitreous; fracture surfaces commonly waxy.
GB/T 34098—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-20
- Source
- GB/T 34098—2017 Quartzose jade — Classification and nomenclature (GB/T): §5.5 (locator checked 2026-09-17)
- Fact checked on
- 2026-09-20
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
This material (RI / SG midpoints): 1.548 / 2.67; Closest values: 1Agate 1.537 / 2.63, 2Shoushan Stone 1.56 / 2.7, 3Changhua Stone 1.56 / 2.6, 4Bamboo Coral 1.57 / 2.65, 5Synthetic Beryl 1.57 / 2.69
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.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- AQSIQ / SAC (China). GB/T 34098—2017 Quartzose jade — Classification and 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 (Silicified Asbestos) 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
- 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 |
| Treatments recorded for this material | Dyed, Filled / Fracture-filled | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Silicified Asbestos 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.