On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Magnesite
An IMA-approved magnesium carbonate mineral species; on the market it is often dyed to imitate Turquoise or Coral, and treatment must be disclosed. 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 Magnesite 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 MagnesiteIdentification points from the research literature; how far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Magnesite1 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing MagnesiteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Mohs hardness of MagnesiteEach value with its source and check date
- Magnesite 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 MagnesiteWhere the name comes from
- Listing and disclosing MagnesiteThe listing name to use; what must be disclosed before sale
- Standard clauses that define MagnesiteWhich 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
Magnesite is a carbonate mineral of formula MgCO3 that belongs to the calcite group. It appears as a primary mineral in igneous or sedimentary rocks, and forms through metamorphism or alteration of serpentine and peridotite; it is uncommon in marine evaporites and hydrothermal veins and rare in carbonatites. Typically earthy, chalky, porcelaneous, fibrous or granular to compact massive, it seldom develops crystals; its colour runs from colourless and white through pale yellow and pale brown to faintly pink and lilac-rose, and under UV light it can show fluorescence and phosphorescence in pale green to pale blue, and it is triboluminescent.
Scope: Applies to the genesis, occurrence, composition and optical phenomena of natural magnesite as a mineral species; does not cover the production of industrial refractory-grade magnesia products.
Sources Handbook of Mineralogy
Where it forms
Occurs as a primary mineral within igneous and sedimentary rocks.
Sources Handbook of Mineralogy
Arises through metamorphism or alteration of serpentine and peridotite.
Sources Handbook of Mineralogy
Only occasionally found in marine evaporites and hydrothermal veins, and rare in carbonatites.
Sources Handbook of Mineralogy
How it forms, step by step
In igneous or sedimentary settings, magnesium combines with carbonate to crystallize magnesite.
Sources Handbook of Mineralogy
Metamorphism or alteration of serpentine and peridotite releases magnesium that forms magnesite.
Sources Handbook of Mineralogy
In specific settings such as evaporites, hydrothermal veins, or carbonatites, magnesite forms in smaller amounts.
Sources Handbook of Mineralogy
Link to appearance
Magnesite is mostly earthy, chalky, porcelaneous, fibrous, or compact massive, with crystals uncommon; its color is colorless, white, pale yellow, pale brown to faintly pink and lilac-rose. Under UV it may show pale green to pale blue fluorescence and phosphorescence and is triboluminescent, responses tied to its composition and crystal structure.
Sources Handbook of Mineralogy
Timescale
The source states no absolute geological timescale for magnesite formation.
Sources Handbook of Mineralogy
Supporting findings
Magnesite is a primary mineral in igneous or sedimentary rocks, is formed by the metamorphism or alteration of serpentine and peridotite, is uncommon in marine evaporites and hydrothermal veins, and is rare in carbonatites.
Evidence grade BScope: Describes magnesite's several natural formation pathways.
Sources Handbook of Mineralogy
Magnesite is commonly associated with talc, antigorite, chlorite, dolomite, and calcite.
Evidence grade BScope: Describes magnesite's associations and occurrence context.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Liaoning, ChinaHoM describes this as a (commercial) deposit of magnesite as magnesium ore/refractory raw material, not as a gem source
Sources Handbook of Mineralogy
Europe
- Magnesia, GreeceSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Baldissero Canavese, Piedmont, ItalySpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Sunk, near Trieben, Styria, AustriaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Radenthein, Carinthia, AustriaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Snarum, NorwaySpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
North America
- Mt. Brussilof mine, near Radium, British Columbia, CanadaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Del Oro deposits, Timmins, Ontario, CanadaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Near Gabbs, Nye County, Nevada, United StatesHoM describes this as a (commercial) deposit of magnesite as magnesium ore/refractory raw material, not as a gem source
Sources Handbook of Mineralogy
- Red Mountain district, Stanislaus and Santa Clara counties, California, United StatesHoM describes this as a (commercial) deposit of magnesite as magnesium ore/refractory raw material, not as a gem source
Sources Handbook of Mineralogy
- southwest of Chewelah, Stevens County, Washington, United StatesSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
South America
- Brumado area, Bahia, BrazilSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial 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.
Causes of colour and optical effects
Under UV light magnesite can show fluorescence and phosphorescence in pale green to pale blue, and it is triboluminescent.
Evidence grade BScope: Describes magnesite's UV luminescence; the source gives no specific mechanism.
Sources Handbook of Mineralogy
Magnesite's color is colorless, white, pale yellow, pale brown to faintly pink and lilac-rose.
Evidence grade BScope: Describes magnesite's color range; the source lists no specific chromophore.
Sources Handbook of Mineralogy
Where the name comes from
Magnesite is named for magnesium in its composition.
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
How it is identified
Turquoise is often imitated by dyeing common minerals such as howlite or magnesite, and infrared (FTIR) spectra clearly distinguish turquoise from these imitations. A trade nomenclature table lists magnesite as dyed almost always.
Evidence grade AScope: Describes identification features reported by a laboratory or educational source; it is not a test that a reader can rely on, and any single piece can only be identified by a gemmological laboratory.
Sources G&G Winter 2024 · CIBJO Gemstone Book 2022
Other research findings
Magnesite has the formula MgCO3, belongs to the calcite group, and forms two series, with gaspeite and with siderite.
Evidence grade BScope: Concerns magnesite's composition and group.
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 age or specific P-T conditions for magnesite formation.
- The source lists no physical mechanism for magnesite's luminescence nor specific chromophores.
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
- Magnesite
GB/T 16552—2017 5.1.1 b) · IMA Mineral List 2026-07 “Magnesite”
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
Magnesite is Magnesite (IMA mineral species); use "Magnesite" 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 "Magnesite" 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
Care
Magnesite — care (chemicals): oxford's Mineral Susceptibility Database records that magnesite dissolves readily in warm, dilute acid (after King 1983), so it is acid-sensitive. This concerns the mineral itself, not dyed or resin-treated material.
Mineral Sensitivity Database, Oxford (2021)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- K. Royce, “The Mineral Susceptibility Database” (MSD-2021.06), University of Oxford (2021), doi:10.5287/bodleian:r17kVJb7d: p.53, body text (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Common care questions and matching entries
Each question links to the matching entries on this page; whether they answer it fully, go by the entry wording.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Contact with acids, alkalis and household chemicals | oxford's Mineral Susceptibility Database records that magnesite dissolves readily in warm, dilute acid (after King 1983), so it is acid-sensitive. This concerns the mineral itself, not dyed or resin-treated material |
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
3.5–4.5
Toughness
Brittle
Cleavage
{1011} perfect
Treatments and identification leads
Values not givenThe registered treatment for Magnesite is dyeing, with the status treated and prevalence “almost always”; stability, identification leads and source are all “—”, meaning the cited source gives no value, not “none”. SyntheticsOn identification, it is registered that there is no synthetic Magnesite on the market.
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| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| dyeingStatus: treated | almost always | — | — | — | — |
Where each treatment acts (schematics): Dyed
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022
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
Standard and listing namesFor the Chinese national standard name, Magnesite is not listed in Annex A, and under the naming rules of GB/T 16552—2017 it may be named directly by its mineralogical name, which in Chinese is the term for magnesite; the mineralogical name is Magnesite (IMA mineral species). The suggested listing name is Magnesite. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Magnesite) and Japanese; the GSJ (Japan) formal name is recorded in its own Japanese form. Institution usageOn authority wording, among GIA, FTC, CIBJO and Gem-A, CIBJO records Magnesite (CIBJO Gemmological Laboratories Book 2024); there is no wording for this name in the FTC text on file (checked); GIA and Gem-A are unchecked. Bodies without a recorded wording show the entry's own English name, which does not represent their position.
- GSJ (Japan) formal name
- 菱苦土石
- Mineral / material name (not in GB/T 16552 Annex A; usable directly)
- 菱镁矿 (GB/T 16552—2017 §5.1.1 b))
- Mineralogical name
- Magnesite (IMA mineral species)
Four-language names
- 简体中文
- 菱镁矿
- 繁體中文
- 菱鎂礦
- English
- Magnesite
- 日本語
- マグネサイト／菱苦土鉱
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Carbonate minerals
- Identity tier
- Mineral species
- Mineral chemical class
- Carbonates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The nomenclature status of Magnesite is IMA status A, meaning a mineral species approved after the IMA was founded in 1958; the composition (phase) is registered as magnesite. Transparency is registered as transparent, with massive white, yellowish to brownish or grey material translucent. For body colour, untreated magnesite is colourless and transparent, while massive white, yellowish to brownish or grey material is translucent. This site notes that in Chapter 7 of the CIBJO Gemmological Laboratories Book the colour descriptions of entries such as dolomite, moonstone and datolite also mention colourless.
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
Magnesite — 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
Magnesite — composition (phase): magnesite
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Optical
Magnesite — transparency: transparent; also massive, white, yellowish to brown or grey, translucent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Magnesite — body colour: Colourless, transparent; also massive, white, yellowish to brown or grey, translucent.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Dolomite, Moonstone, Datolite and other entries also name colourless.
- 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
For Magnesite in any treatment state, no synthetic counterpart is available on the market. For treated Magnesite, the reported frequency of dyeing in trade is “almost always”, and the identification lead for dyeing is recorded in the original as “—”, meaning the cited source gives no value. The CIBJO laboratory protocol requires checks focused on Magnesite: the crystalline variety is very soft, and the massive variety is often dyed.
The tests the CIBJO laboratory protocol requires for this material, and what each method means, are in the protocol table on the laboratory testing page: §6.1.50.
How far testing can go
Magnesite — 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
For Magnesite in trade, the reported frequency of dyeing is “almost always”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- dyeing
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Magnesite — what the CIBJO laboratory protocol says to watch for: crystalline variety very soft, massive variety often used with dye.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- 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.
Clause-level definitions
Magnesite has a clause-level definition in CIBJO Gemmological Laboratories Book 2024 under the entry name Magnesite, defined as mineral species magnesite with IMA status A, with the CIBJO wording quoted in full under Clause-level definitions on this page. The cross-check result is that it is defined directly by CIBJO, and no identically named English entry was found in the GB/T annex. In the IMA Mineral List, Magnesite is recorded as Magnesite Mg(CO3) A 1962 s.p., cross-checked against RRUFF and the IMA master mineral list; the data are public domain.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Magnesite | 7.2.1.135 | Colourless, transparent; also massive, white, yellowish to brown or grey, translucent. Dyed blue to imitate turquoise | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Magnesite | IMA Mineral List entry | Magnesite Mg(CO3) A 1962 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 | Carbonate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Magnesite 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.