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Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Kosmochlor
A separate mineral species of the pyroxene group and one of the minor constituent minerals of jadeite jade; the name cannot be used for just any chromium-bearing green aggregate. 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 Kosmochlor forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify KosmochlorHow far lab testing can go and whether a synthetic exists
- Caring for and wearing KosmochlorDurability indicators and wearing advice
- Mohs hardness of KosmochlorEach value with its source and check date
- Kosmochlor in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Which of GIA, FTC, CIBJO and Gem-A have a name for it on record, and do those agree?
- Name origin and history of KosmochlorWhere the name comes from
- Listing and disclosing KosmochlorThe listing name to use; what must be disclosed before sale
- Standard clauses that define KosmochlorWhich clause defines it, each cross-checked
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
Kosmochlor is a pyroxene-group mineral with a formula of about NaCr3+Si2O6 (a sodium–chromium single-chain silicate). It is known from two contrasting settings: as a major constituent of some jadeitites, and as an accessory constituent of some iron meteorites (such as Toluca, Coahuila, and Canyon Diablo). Crystals are short prismatic (to 2 mm) and it also occurs as fibrous and polycrystalline aggregates. It is recognized as an independent mineral species, its name referencing its meteoritic occurrence and its green color.
Scope: Applies to an overview of the genesis and occurrence of kosmochlor as a separate mineral species of the pyroxene group; does not cover synthetics or imitations.
Sources Handbook of Mineralogy
Where it forms
In some jadeitites, associated with jadeite, chromite, chlorite, and others (e.g. around Tawmaw, Myanmar)
Sources Handbook of Mineralogy
In some iron meteorites, as an accessory mineral, associated with graphite (cliftonite), chromian diopside, troilite, daubréelite, and others
Sources Handbook of Mineralogy
How it forms, step by step
Na, Cr, Si, and other components are supplied in the (high-pressure) metamorphic environment where jadeitite forms.
Sources Handbook of Mineralogy
Kosmochlor crystallizes in the jadeitite, becoming one of its major constituents.
Sources Handbook of Mineralogy
In some iron meteorites, kosmochlor occurs as an accessory mineral alongside graphite, troilite, and others.
Sources Handbook of Mineralogy
Crystals are short prismatic and it also occurs as fibrous and polycrystalline aggregates.
Sources Handbook of Mineralogy
Link to appearance
Kosmochlor is emerald-green, green or yellow in thin section, and shows strong pleochroism (X yellowish green; Y blue-green to grass-green; Z emerald-green); its name joins the German kosmisch (cosmic, alluding to its meteoritic occurrence) and the Greek chlor (green). The source gives no color-cause mechanism.
Sources Handbook of Mineralogy
Timescale
The source states no absolute geological timescale for kosmochlor formation.
Sources Handbook of Mineralogy
Supporting findings
Kosmochlor is a major constituent of some jadeitites and an accessory constituent of some iron meteorites.
Evidence grade BScope: Describes the two known settings; not an exhaustive list of localities.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Hex River Mountains meteorite, South AfricaOccurs in the meteorite; location is the meteorite find site, not a gem source
Sources Handbook of Mineralogy
Asia
- Tawmaw area, Myitkyina–Mogaung district, Kachin State, MyanmarSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
Europe
- Mocchie, Susa, Piedmont, ItalySpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
North America
- Williams Creek, Mendocino County, California, United StatesSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Toluca meteorite (Xiquipilco area), MexicoOccurs in the meteorite; location is the meteorite find site, not a gem source
Sources Handbook of Mineralogy
- Coahuila meteorite, Coahuila, MexicoOccurs in the meteorite; location is the meteorite find site, not a gem source
Sources Handbook of Mineralogy
- Canyon Diablo meteorite, Arizona, United StatesOccurs in the meteorite; location is the meteorite find site, not a gem source
Sources Handbook of Mineralogy
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.
Where the name comes from
Kosmochlor joins the German word kosmisch — 'cosmic', a reference to its meteoritic occurrence — with the Greek chlor, meaning 'green'.
Evidence grade BScope: The etymology explains the origin of a name only; it does not attest composition, locality, naturalness or treatment.
Sources Handbook of Mineralogy
Other research findings
Kosmochlor is a pyroxene-group mineral with a formula of about NaCr3+Si2O6, a sodium–chromium single-chain silicate.
Evidence grade BScope: Describes composition and group affiliation; not an exact composition of a specific specimen.
Sources Handbook of Mineralogy
Kosmochlor is an independent pyroxene-group mineral species; crystals are short prismatic and it also occurs as fibrous and polycrystalline aggregates, and it shows strong pleochroism.
Evidence grade BScope: Defines kosmochlor's species status, habit, and pleochroism.
Sources Handbook of Mineralogy
Kosmochlor takes its name from the German kosmisch (cosmic, alluding to its meteoritic occurrence) and the Greek chlor (green).
Evidence grade BScope: Concerns naming origin, not geological formation.
Sources Handbook of Mineralogy
Kosmochlor is emerald-green, green or yellow in thin section, and shows strong pleochroism.
Evidence grade BScope: Describes color and pleochroism; the source gives no color-cause mechanism.
Sources Handbook of Mineralogy
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The source states no absolute geological timescale for kosmochlor formation.
- The source gives no specific color-cause mechanism for kosmochlor.
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
- Kosmochlor
GB/T 16552—2017 5.1.1 b) · IMA Mineral List 2026-07 “Kosmochlor”
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
Kosmochlor is Kosmochlor (IMA pyroxene-group mineral species); use "Kosmochlor" for listings, and disclose any known treatments.
Evidence
- GB/T · 5.1.1 b)
What this means for you
Before buying, check the recommended listing name "Kosmochlor" 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
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.
Mohs hardness
≈6
Cleavage
{110} good, intersecting at about 87°; parting on {001}
Sources Handbook of Mineralogy
Daily wear
Kosmochlor is about Mohs 6 with good cleavage; wearable daily but to be protected from scratching and from cleavage-related impact fracture.
Care
Clean with warm water, mild soap and a soft brush; avoid ultrasonic/steam cleaners, chemicals and impact.
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 general material properties and does not constitute a durability or safety warranty for any specific finished product; the durability of treated (filling/dyeing/coating) or assembled pieces must be assessed separately.
How lab reports word it
Report wording for Kosmochlor is set out under report wording on the Fei Cui / Jadeite Jade entry.
VerifyNames, standards, technical facts, clauses and sources
Names
Trade and mineralogical namesThe mineralogical name of Kosmochlor is Kosmochlor, an IMA mineral species of the pyroxene group; the Chinese formal name corresponds to the "Fei Cui" (jadeite jade) row of GB/T 16552—2017 Table A.2. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Kosmochlor) and Japanese. Recommended listing nameThe suggested listing name is Kosmochlor. Institution usageOn authority wording, CIBJO Gemmological Laboratories Book 2024 includes Kosmochlor; the FTC text contains no wording for this name; GIA and Gem-A are unchecked, and bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe entry has its own Japanese name, and the wording used by GSJ (Japan) for this name is not yet verified by this site.
- GSJ (Japan) formal name
- コスモクロア／曹達クロム輝石 (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 钠铬辉石 (GB/T 16552—2017 Table A.2, row “Feicui,Jadeite”)
- Mineralogical name
- Kosmochlor (IMA pyroxene-group mineral species)
Four-language names
- 简体中文
- 钠铬辉石
- 繁體中文
- 鈉鉻輝石
- English
- Kosmochlor
- 日本語
- コスモクロア／曹達クロム輝石
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Jade materials
- Identity tier
- Mineral species
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The registered material facts for Kosmochlor cite the CIBJO Gemmological Laboratories Book (Gemmological Commission 2024-1): the nomenclature status is IMA status A, a mineral species approved after the IMA was set up in 1958; the composition (phase) is registered as kosmochlor; transparency translucent to opaque; body colour bright to dark green, with the treatment state for body colour untreated. This site also notes that in chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions for entries such as aventurine, diopside and emerald also mention green or a greenish tint.
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
Kosmochlor — nomenclature status: IMA status A: approved (accepted by the IMA after it was set up in 1958).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Kosmochlor — composition (phase): kosmochlor
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Optical
Kosmochlor — transparency: translucent to opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Kosmochlor — body colour: bright to dark green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Aventurine Quartz, Diopside, Emerald and other entries also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Testing and market
The testing and market finding registered for Kosmochlor is that no synthetic counterpart of Kosmochlor is available on the market. The source is the Kosmochlor entry in Annex C of the CIBJO Blue Book — Official Gemstone Book (2022), with code N from Annex B; the treatment state is any treatment state.
How far testing can go
Kosmochlor — synthetic counterpart on the market: No synthetic counterpart of this material is commercially available
CIBJO Gemstone Book 2022
- Treatment state
- any treatment state
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Kosmochlor is listed in the CIBJO Gemmological Laboratories Book 2024 under the term Kosmochlor, defined as bright to dark green, translucent to opaque; the cross-check result is that it is defined directly by CIBJO, and no identically named English entry was found in this edition of the GB/T annex. The IMA mineral list also has an entry named Kosmochlor, giving the mineral name Kosmochlor and the chemical formula NaCr3+Si2O6, with status code A and the year 1988; the cross-check is against the main table of the RRUFF/IMA mineral list, which is public-domain data.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Kosmochlor | 7.2.1.122 | bright to dark green, translucent to opaque | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Kosmochlor | IMA Mineral List entry | Kosmochlor NaCr3+Si2O6 A 1988 s.p. | Cross-checked against the RRUFF/IMA master mineral list (public domain data). |
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.
- RRUFF Project, in partnership with the IMA – International Mineralogical Association. IMA Mineral List.
- Geological Survey of Japan, AIST (Japan). Museum mineral specimens, browse by classification.
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 | Jade materials | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Kosmochlor 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; clause-level definitions also carry a cross-check result. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.