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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Aragonite
Also known asAragonite Satin Spar · Fibrous aragonite
A CaCO3 mineral species that is a polymorph of calcite; it is also the main component of the nacre layers in pearls. 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 Aragonite 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 AragoniteHow far lab testing can go
- Caring for and wearing AragoniteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Mohs hardness of AragoniteEach value with its source and check date
- Aragonite 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 AragoniteWhere the name comes from
- Listing and disclosing AragoniteThe listing name to use; what must be disclosed before sale
- Standard clauses that define AragoniteWhich 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
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.
Aragonite is a carbonate mineral of formula CaCO3 that belongs to the aragonite group and is one of the CaCO3 polymorphs: it is trimorphous with calcite and vaterite. Aragonite is orthorhombic, while calcite — the same composition in a different crystal system — is trigonal. Aragonite is stable where pressure is higher and temperature lower, typifies the high-pressure, low-temperature conditions of blueschist-facies metamorphism, and converts to calcite over geologic time. It precipitates chiefly in warm marine waters, taking the form of oolites and carbonate mud, and becomes a chief constituent of the hard parts of numerous marine micro-organisms, shells and skeletons; it also occurs in evaporite deposits, in hot-spring sinter and in cave dripstone.
Scope: Applies to the genesis, occurrence, composition and polymorphic relationships of natural aragonite as a mineral species, and makes explicit its CaCO3 polymorphic relationship with calcite; does not cover gemmological identification of biomineralised materials or nacre.
Sources Handbook of Mineralogy
Where it forms
Forms chiefly in warm marine waters, where it appears as oolites and carbonate mud, and makes up the hard parts of numerous marine micro-organisms, shells and skeletons.
Sources Handbook of Mineralogy
Typical of metamorphic conditions that combine elevated pressure with low temperature (blueschist facies).
Sources Handbook of Mineralogy
Evaporite deposits, hot-spring sinter, and cave dripstone; amygdules in basalt and andesite and altered ultramafic rocks
Sources Handbook of Mineralogy
How it forms, step by step
In warm marine waters, calcium and carbonate precipitate as aragonite (e.g., oolites and carbonate mud), and organisms use it to build shells and skeletons.
Sources Handbook of Mineralogy
Under higher-pressure, lower-temperature metamorphic conditions (blueschist facies), aragonite is stable and becomes a characteristic mineral.
Sources Handbook of Mineralogy
Over geologic time, aragonite (a metastable CaCO3 polymorph) converts to the more stable calcite.
Sources Handbook of Mineralogy
Link to appearance
Aragonite is orthorhombic (pseudohexagonal); its crystals are typically prismatic, acicular, or tabular and form pseudohexagonal columnar trillings through repeated contact twinning on {110}; aggregates may be columnar, globular, reniform, pisolitic, coralloidal, or stalactitic, often internally fibrous or banded. It is colorless to white, also gray and pale yellow, blue, violet, green, or red, with a vitreous luster and a resinous luster on fracture surfaces.
Sources Handbook of Mineralogy
Timescale
The source states that aragonite converts to calcite over geologic time but gives no specific absolute age.
Sources Handbook of Mineralogy
Supporting findings
Aragonite precipitates chiefly in warm marine waters, taking the form of oolites and carbonate mud, and becomes a chief constituent of the hard parts of numerous marine micro-organisms, shells and skeletons; it also occurs in evaporite deposits, in hot-spring sinter and in cave dripstone, and typifies the high-pressure, low-temperature conditions of blueschist-facies metamorphism.
Evidence grade BScope: Describes aragonite's natural formation pathways and environments.
Sources Handbook of Mineralogy
Aragonite is commonly associated with gypsum, sulfur, and celestine (evaporites); pumpellyite, lawsonite, glaucophane, and quartz (blueschist); and calcite, dolomite, hydromagnesite, brucite, and magnesite (altered ultramafics).
Evidence grade BScope: Describes aragonite's associations by environment.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Touissit mine, near Oujda, MoroccoSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Tazouta, near Sefrou, MoroccoSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Tsumeb, NamibiaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
Europe
- Molina, Guadalajara, SpainSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Racalmuto, Cianciana and Agrigento, Sicily, ItalySpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Špania Dolina (Herrengrund), SlovakiaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Tarnowskie Góry (Tarnowitz), Silesia, PolandSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Erzberg, near Eisenerz, Styria, AustriaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Leogang, Salzburg, AustriaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Spitzberg, near Bílina, CzechiaSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Frizington and Cleator Moor, Cumbria, England, United KingdomSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Aragón, SpainFirst-noted occurrence and source of the name (HoM Name field); not a commercial source
Sources Handbook of Mineralogy
North America
- Bisbee, Arizona, United StatesSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- near Lake Arthur and Santa Rosa, New Mexico, United StatesSpecimen/occurrence locality listed by the Handbook of Mineralogy; not a commercial gem source
Sources Handbook of Mineralogy
- Passaic mine, Sterling Hill, Ogdensburg, New Jersey, United StatesSpecimen/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
Aragonite is colorless, white, and also gray and pale shades of yellow, blue, violet, green, and red; it may be cathodoluminescent, fluoresce red or yellow under long- and short-wave UV, and be phosphorescent.
Evidence grade BScope: Describes aragonite's luminescence; the source gives no specific mechanism.
Sources Handbook of Mineralogy
Where the name comes from
Aragonite's name points to Aragon in Spain, the region where the mineral was first recorded.
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
Aragonite has the formula CaCO3, belongs to the aragonite group, and is trimorphous with calcite and vaterite.
Evidence grade BScope: Concerns aragonite's composition and polymorphism.
Sources Handbook of Mineralogy
Aragonite and calcite are polymorphs of CaCO3: aragonite is orthorhombic, while calcite is a polymorph of the same composition but a different crystal system (trigonal); aragonite is stable under higher-pressure, lower-temperature (blueschist-facies) conditions and converts to calcite over geologic time.
Evidence grade BScope: Defines the aragonite-calcite polymorph relationship; the crystal-system contrast is standard mineralogy.
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 for aragonite formation or its conversion to calcite.
- The source gives no physical mechanism for aragonite's luminescence.
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
- Aragonite
GB/T 16552—2017 5.1.1 b) · IMA Mineral List 2026-07 “Aragonite”
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
Aragonite is Aragonite (IMA mineral species, CaCO3 polymorph); use "Aragonite" 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 "Aragonite" 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
Normal care for every gemstone (CIBJO Gemstone Book §6.1), in brief:
- Handle it gently.
- Store pieces apart when not worn, so they cannot scratch each other.
- Clean with warm soapy water and a soft brush.
- Use ultrasonic cleaners only with caution.
The §6.1 wording and the full list of §6.2 special-care letters cited on this page are on the general gem care page.
Care
Aragonite — care (cleaning): Some stones are susceptible to damage from ultrasonic cleaning. Do not expose them to ultrasonic cleaning.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code j
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Aragonite, p.34; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Aragonite — care (chemicals): Some stones are particularly susceptible to attack by acids. Keep them away from acids.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code h
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Aragonite, p.34; §6.2 h (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Aragonite — care (wear): Some stones are prone to scratching due to low hardness. Wear them with care.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code a
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Aragonite, p.34; §6.2 a (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
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
CleaningOn care for Aragonite, the CIBJO Gemstone Book (2022) states that Aragonite must not be cleaned ultrasonically; it is particularly sensitive to acids and should be kept away from them; and it is soft and scratches easily, so wear it with care. All the care conclusions the CIBJO Gemstone Book gives for Aragonite apply in any treatment state, to treated and untreated Aragonite alike, with no restriction to a particular treatment state or type of Aragonite. General careGeneral care that applies to all gemstones, and the full table of special-care letters in the CIBJO Gemstone Book, are in the general care section of the materials index page.
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| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | care (cleaning) |
| Contact with acids, alkalis and household chemicals | care (chemicals) |
| Wearing limits (knocks, settings) | care (wear) |
Durability and wearing
Mohs hardness
3.5–4
Toughness
Brittle
Cleavage
{010} distinct; {110} and {011} imperfect
Sources Handbook of Mineralogy
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Aragonite, the name register records "Aragonite Satin Spar" and "Fibrous aragonite", for which no restriction on use as a name is recorded (CIBJO Gemstone Book 2022 Annex 8 “Aragonite Satin Spar”; CIBJO Gemstone Book 2022 Annex 8 “Fibrous aragonite”).
Standard and listing namesAragonite can be named directly under GB/T 16552—2017: Annex A does not list Aragonite, and under the standard's naming rules a mineral name not in Annex A can be used directly as a gem material name. The suggested listing name is Aragonite. Trade and mineralogical namesIts mineralogical name is Aragonite, an IMA mineral species and a polymorph of CaCO3. Names in four languagesOf the four-language names, Simplified and Traditional Chinese share the same name, the English is Aragonite, and the Japanese is a transliteration and a kanji name; the Japanese GSJ formal name is the kanji name. Institution usageAmong authority wordings, CIBJO's wording is recorded as Aragonite (CIBJO Gemmological Laboratories Book 2024); the FTC source text has no wording for this name (checked); GIA and Gem-A have not been checked; bodies without a recorded wording are shown as Aragonite, which does not represent their position. Sub-names and unacceptable namesEnglish also has the market name Aragonite Satin Spar and the subordinate name Fibrous aragonite.
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.
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| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (2) | ||||
| Aragonite Satin SparEnglish | market name | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Aragonite Satin Spar” |
| Fibrous aragoniteEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Fibrous aragonite” |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 霰石
- Mineral / material name (not in GB/T 16552 Annex A; usable directly)
- 文石 (GB/T 16552—2017 §5.1.1 b))
- Mineralogical name
- Aragonite (IMA mineral species, CaCO3 polymorph)
- Trade names and synonyms
- Aragonite Satin Spar (market name) · Fibrous aragonite (narrower name (variety or subtype))
Four-language names
- 简体中文
- 文石
- 繁體中文
- 文石
- English
- Aragonite
- 日本語
- アラゴナイト／霰石
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
Among the registered material facts for Aragonite, its nomenclature status under the IMA is status G, meaning grandfathered: described before the IMA existed and generally regarded as a valid species; composition (phase) is registered as aragonite. Optically, Aragonite is transparent to opaque; untreated, its body colour is colourless, white, grey, pink, and light tones of yellow, brown, green, blue and violet-blue. In Chapter 7 of the CIBJO Gemmological Laboratories Book 2024, the colour descriptions for entries such as smithsonite, apatite and amblygonite 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
Aragonite — nomenclature status: IMA status G: grandfathered (described before the IMA existed, and generally regarded as a valid species).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Aragonite — composition (phase): aragonite
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Optical
Aragonite — transparency: transparent to opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Aragonite — body colour: Colourless, white, grey, pink, light tones of yellow, brown, green, blue, violet.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Smithsonite, Apatite, Amblygonite 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 the identification of Aragonite, the CIBJO laboratory protocol (Gemmological Laboratories Book 2024) requires dyeing to be checked in particular. Which tests the CIBJO laboratory protocol requires for Aragonite, and what each method means, are set out in the protocol table on the laboratory testing page.
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: §6.1.9.
How far testing can go
Aragonite — what the CIBJO laboratory protocol says to watch for: 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
Aragonite has a direct definition in the list of gem materials and definitions of the CIBJO Gemmological Laboratories Book 2024 under the term Aragonite: mineral species aragonite, IMA status G, with the CIBJO wording quoted in full under Clause-level definitions on this page; the cross-check result is a direct CIBJO definition, with no identically named English entry found in this edition of the GB/T annex. The IMA Mineral List entry for Aragonite is Aragonite Ca(CO3) G 1791; it is cross-checked against the RRUFF/IMA master mineral list, on the basis of public domain data.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Aragonite | 7.2.1.22 | Colourless, white, grey, pink, light tones of yellow, brown, green, blue, violet; transparent to opaque | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Aragonite | IMA Mineral List entry | Aragonite Ca(CO3) G 1791 | 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.
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| Page | Content | Status |
|---|---|---|
| Browsing family | Carbonate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Aragonite 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.