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Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown

Pyrite

Also known asFool’s gold

A mineral species with the formula FeS2; its edges are fairly brittle, and care is needed when wearing it with sweat or in damp conditions. 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.

Edited by JuneReviewed by RalphLast updated 2026-10-12Who maintains this page

FAQCare and wear

Questions people ask about Pyrite

Every sentence below is followed by the registered fact it rests on; answers add no new facts and promise no outcome.

Q1Is pyrite the same as fool's gold, and how does it differ from gold?

Yes: pyrite is pale brass-yellow with a bright metallic lustre and is nicknamed fool's gold because it is often mistaken for gold.Handbook of MineralogyIts streak is greenish black to brownish black.Handbook of MineralogyChemically it is iron sulfide, FeS2.Handbook of Mineralogy

Q2Can pyrite get wet, and why does it sometimes crumble?

Above 60% relative humidity pyrite reacts with moisture in the air, forming hydrated iron sulphate and possibly a weak sulphuric acid.NatSCA Care and Conservation of Geological Specimens (2013)Natural history conservators advise keeping pyrite below 60% relative humidity, ideally at 45% or less, because this so-called pyrite decay can reduce a specimen to powder.NatSCA Care and Conservation of Geological Specimens (2013)

Q3How hard and durable is pyrite?

Its hardness is recorded as Mohs 6–6.5.Handbook of MineralogyIt is brittle.Handbook of MineralogyIt breaks with a conchoidal to uneven fracture.Handbook of Mineralogy

Q4How does pyrite form?

Pyrite is the most abundant and widespread sulfide mineral.Handbook of MineralogyIt forms under very varied conditions: in hydrothermal veins and magmatic segregations, in igneous rocks and pegmatites, in metamorphic rocks, and by replacement within sedimentary rocks.Handbook of Mineralogy

Q5Why is pyrite gold-coloured?

Its pale brass-yellow colour and metallic lustre arise from its iron sulfide composition.Handbook of MineralogyCIBJO describes the colour as metallic yellow with a brassy appearance.CIBJO Gemmological Laboratories Book 2024

Q6What does pyrite symbolize, and does it have healing powers?

There is no scientific evidence that pyrite has healing powers: the UK advertising regulators ASA and CAP state that they have not seen evidence that crystal therapy can treat medical conditions.ASA/CAP guidance (UK)What is recorded is the origin of its name: it comes from the Greek for fire, because striking the mineral can give off sparks.Handbook of Mineralogy

What this page can answer

This page covers

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

Pyrite (FeS2) is the most abundant and widespread sulfide mineral. It forms under a wide variety of conditions: as very large hydrothermal vein bodies, magmatic segregations, an accessory mineral in igneous rocks and pegmatites, in contact metamorphic deposits and metamorphic rocks, and as diagenetic replacements in sedimentary rocks. Pyrite is cubic, dimorphous with marcasite, forms a series with cattierite, and belongs to the pyrite group. Its crystals are typically cubic, pyritohedral, and octahedral, with a pale brass-yellow color and metallic luster.

Scope: Covers the origin, occurrence and composition of natural pyrite as a mineral species; does not address synthetic iron disulphide or trade claims about gold-bearing pyrite.

Sources Handbook of Mineralogy

Where it forms

Hydrothermal veins and magmatic segregations; an accessory phase within igneous rocks and pegmatites

Sources Handbook of Mineralogy

Deposits of contact-metamorphic origin, together with metamorphic rocks

Sources Handbook of Mineralogy

Through diagenetic replacement within sedimentary rocks

Sources Handbook of Mineralogy

How it forms, step by step

  1. In hydrothermal and magmatic environments, iron and sulfur combine and precipitate in large amounts to form pyrite.

    Sources Handbook of Mineralogy

  2. During contact metamorphism and metamorphism, pyrite occurs as an accessory mineral or as ore bodies.

    Sources Handbook of Mineralogy

  3. During diagenesis in sedimentary rocks, pyrite forms by replacement (e.g., framboidal or globular aggregates).

    Sources Handbook of Mineralogy

Link to appearance

Pyrite is pale brass-yellow with a metallic, splendent luster and a greenish black to brownish black streak; it is nicknamed 'fool's gold' because it is often mistaken for gold. Its crystals are typically cubic, pyritohedral, and octahedral, with granular, globular, and framboidal aggregates and striations conforming to pyritohedral symmetry.

Sources Handbook of Mineralogy

Timescale

The source states no absolute geological timescale for pyrite formation.

Sources Handbook of Mineralogy

Supporting findings

Pyrite is produced under very varied conditions: in hydrothermal veins and magmatic segregations; as an accessory phase within igneous rocks and pegmatites; in contact-metamorphic and metamorphic rocks; and through diagenetic replacement within sedimentary rocks.

Evidence grade B

Scope: Describes pyrite's diverse natural formation pathways.

Sources Handbook of Mineralogy

Recorded localities

Authoritative sources list the localities below; the list is not exhaustive.

Locality sketch mapLand outlines only; the map does not depict any national or regional boundary. Dots mark approximate positions. Base map: Natural Earth (public domain).

Asia

  • Aktchitao, KazakhstanMineral specimen locality (not a source of jewellery material) · not on the mapExact position not given; not plotted
    Sources Handbook of Mineralogy

Europe

North America

South America

Seas and coasts

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

Pyrite is pale brass-yellow with a greenish black to brownish black streak and metallic, splendent luster, its color and luster arising from its iron sulfide composition.

Evidence grade B

Scope: Describes the compositional basis of pyrite's color.

Sources Handbook of Mineralogy

Where the name comes from

Pyrite's name is Greek for "fire", since striking the mineral can give off sparks.

Evidence grade B

Scope: This states only the origin of the name and does not establish the material's composition, locality, natural origin, or whether it was treated.

Sources Handbook of Mineralogy

Human use and museum objects

Only four collection objects are recorded as pyrite, all from the Americas (Met 1987.394.28 Moche owl; Met 1979.206.1064 Chiriquí pendant; Met 1979.206.1015 Huastec earflare frontal, inlays probably pyrite; and Cleveland 1989.65 mirror back), the 'probably pyrite' notation retaining its uncertainty; the sparse evidence cannot summarise a general history of use.

Evidence grade A

Scope: Applies to the few American collection objects labelled pyrite; the museum's 'probably pyrite' notation retains its uncertainty, with no further inference drawn.

Sources The Met 1987.394.28 · The Met 1979.206.1064 · The Met 1979.206.1015 +1

Only four objects in the collection are explicitly recorded as pyrite, all from the Americas (Andean and Mesoamerican), with no Old World ancient instance. A Moche 'Owl' from Peru (Met 1987.394.28, 6th-7th century CE) includes pyrite; a Chiriquí crocodile-head pendant from Costa Rica (1979.206.1064, 700-1550 CE) is inlaid with pyrite. A Huastec earflare frontal from Mexico (1979.206.1015, 900-1300 CE) is recorded as 'iron-based metal (inlays probably pyrite)', an uncertainty retained here; and the Cleveland Museum of Art's 'Mirror Back with Great Goddess' (1989.65, 400-550 CE) was originally inlaid on the reverse with a polished pyrite mirror. Pyrite here serves mainly as a reflective mirror surface or inlay. The evidence is sparse and is reported as it stands.

Sources The Met 1987.394.28 · The Met 1979.206.1064 · The Met 1979.206.1015 +1

Scope: A museum object evidences only the existence and date of that artefact itself; it does not establish widespread ancient use of the material, nor does it attest the origin, naturalness, or treatment of any modern specimen.

Objects cited

4006008001000120014001600CMA 1989.65400–550 CEMet 1987.394.286th–7th centuryMet 1979.206.1064700–1550 CEMet 1979.206.1015900–1300 CE
Dates of museum objectsDates from the museums' open-access records (CC0); each bar spans the whole period named in the record, with qualifiers such as “early” or “possibly” kept in the label rather than turned into a narrower range; an arrow marks a record that reads “before” or “after” a yearSource: The Met / Cleveland Museum of Art open-access records
  • The Met 1987.394.28Owl · 6th–7th century · Moche · PeruSilvered copper, shell, pyrite
  • The Met 1979.206.1064Crocodile-head figure pendant · 700–1550 CE · Chiriqui · Costa RicaGold (cast alloy), pyrite inlay, hematite
  • The Met 1979.206.1015Earflare Frontal · 900–1300 CE · Huastec · MesoamericaShell, red pigment (cinnabar), iron-based metal (inlays probably pyrite)
  • Cleveland Museum of Art 1989.65Mirror Back with Great Goddess · 400–550 CE · Guatemala(?), Escuintla, Teotihuacán style, Classic Periodslate, pigment; other side originally inlaid with polished pyrite mirror

Other research findings

Pyrite has the formula FeS2, is dimorphous with marcasite, forms a series with cattierite, and belongs to the pyrite group.

Evidence grade B

Scope: Concerns pyrite's composition, polymorphism, and group.

Sources Handbook of Mineralogy

Pyrite's name derives from the Greek word for fire, because sparks can be struck from the stone.

Evidence grade B

Scope: Concerns the name's origin, not genesis.

Sources Handbook of Mineralogy

Pyrite is the most abundant and widespread sulfide mineral.

Evidence grade B

Scope: Describes pyrite's overall abundance status.

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 values for pyrite formation.

Methodology

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
Pyrite

GB/T 16552—2017 5.1.1 b) · CIBJO Gemmological Laboratories Book 2024 §7.2.1.187 “Pyrite”

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

Pyrite is Pyrite (FeS2); use "Pyrite" for listings, and disclose any known treatments.

What this means for you

Before buying, check the recommended listing name "Pyrite" 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

Pyrite — care (chemicals): Above 60% humidity, pyrite reacts with moisture in the air, producing hydrated iron sulphate and potentially a weak sulphuric acid.

NatSCA Care and Conservation of Geological Specimens (2013)

Treatment state
any treatment state
Source & check 2026-10-06
Source
Fact checked on
2026-10-06

Pyrite — care (storage): Specimens containing pyrite should be kept below 60% relative humidity, ideally at 45% or less; so-called pyrite decay can strike rocks, fossils and minerals alike, reducing a specimen to powder.

NatSCA Care and Conservation of Geological Specimens (2013)

Treatment state
any treatment state
Source & check 2026-10-06
Source
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.

QuestionMatching entries
Contact with acids, alkalis and household chemicalsAbove 60% humidity, pyrite reacts with moisture in the air, producing hydrated iron sulphate and potentially a weak sulphuric acid

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

6–6.5

Toughness

Brittle

Cleavage

Indistinct on {001}; partings on {011} and {111}, indistinct

Fracture

Conchoidal to uneven

Sources Handbook of Mineralogy

VerifyNames, standards, technical facts, clauses and sources

Names

Besides Pyrite, the name register records "Fool’s gold", for which no restriction on use as a name is recorded.

Standard and listing namesPyrite is not listed in GB/T 16552—2017 Annex A, and the mineral/material name that can be used directly under GB/T 16552—2017 is pyrite; the suggested listing name is also Pyrite. Trade and mineralogical namesThe mineralogical name is Pyrite, formula FeS2; the trade name or synonym Fool’s gold is also a market name. Japanese namesThe formal name of Japan's GSJ is written in Japanese. Names in four languagesFour-language names are given in Simplified Chinese, Traditional Chinese, English (Pyrite) and Japanese. Institution usageOn authority wording, CIBJO Gemmological Laboratories Book 2024 records Pyrite; the FTC text on file has no wording for this name (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.

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.

NameTypeMatchingUse as a nameBasis
no restriction recorded (1)
Fool’s goldEnglishmarket namematched automaticallyno restriction recordededitorial ruling (no clause cited)

How each authority words this name: see Names › Authority wording.

Authority wording

GIA, FTC, CIBJO, Gem-A
Pyrite (on record for CIBJO (CIBJO Gemmological Laboratories Book 2024 §7.2.1.187); no wording for this name in the FTC text on file; GIA, Gem-A unchecked — bodies without a recorded wording show the entry's own English name)
GSJ (Japan) formal name
黄鉄鉱
Mineral / material name (not in GB/T 16552 Annex A; usable directly)
黄铁矿 (GB/T 16552—2017 §5.1.1 b))
Mineralogical name
Pyrite (FeS2)
Trade names and synonyms
Fool’s gold (market name)

Four-language names

简体中文
黄铁矿
繁體中文
黃鐵礦
English
Pyrite
日本語
パイライト／黄鉄鉱

See also: Misleading and prohibited trade names · Supplementary name index

Classification

Origin
Natural materials
Material domain
Natural inorganic gem materials
Browsing family
Sulfide minerals
Identity tier
Mineral species
Mineral chemical class
Sulfides / sulfosalts
Construction or treatment status
Natural identity; treatment status unknown

What it is and how it's identified

The IMA nomenclature status of Pyrite is G, meaning grandfathered: described before the IMA existed and generally regarded as a valid mineral species. The composition (phase) is registered as pyrite; transparency opaque; the body colour of untreated Pyrite is metallic yellow, with a brass-like appearance. This site notes that in chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions for entries such as heliodor, chrysoprase and demantoid also mention yellow or yellowish colours.

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

Pyrite — 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

Pyrite — composition (phase): pyrite

CIBJO Gemmological Laboratories Book 2024

Source & check 2026-09-22
Source
Fact checked on
2026-09-22

Optical

Pyrite — transparency: opaque.

CIBJO Gemmological Laboratories Book 2024

Source & check 2026-09-22
Source
Fact checked on
2026-09-22

Pyrite — body colour: metallic yellow (brassy appearance).

CIBJO Gemmological Laboratories Book 2024

Treatment state
untreated
Qualification

In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Heliodor / Golden Beryl, Chrysoprase, Demantoid and other entries also name yellow or a yellowish colour.

General note
colour alone is not identity
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.

Testing and market

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: §6.1.64.

How far testing can go

Pyrite — 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

Pyrite — what the CIBJO laboratory protocol says to watch for: marcasite (misnomer), steel imitation

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

The clause-level definition of Pyrite is registered under the term Pyrite, with the clause being the IMA mineral list entry; the visible definition reads Pyrite FeS2 G ?. The cross-check is against the main table of the RRUFF/IMA mineral list and is noted as public-domain data.

This table scrolls sideways on narrow screens.

TermClauseDefinitionCross-check
PyriteIMA Mineral List entryPyrite FeS2 G ?Cross-checked against the RRUFF/IMA master mineral list (public domain data).

Evidence and sources

Authority basis and clause sources

GB/T 16552—2017
Not listed the name does not occur anywhere in the text; scope: Chapter 1 “Scope” · Source
GB/T 16552—2017
Naming rule 5.1.1 b) · Source
CIBJO Gemmological Laboratories Book 2024
Listed §7.2.1.187 “Pyrite” · Source
IMA Mineral List 2026-07
Listed “Pyrite” · Source

Sources

Further reading

Related intention themes

These reviewed links connect this material with LumaLark intention themes. Each label identifies whether the link is a brand interpretation or a historical and cultural record; neither describes an effect or outcome of the material.

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.

PageContentStatus
Browsing familySulfide mineralsLive
Related articlesTo be added (placeholder)Planned

Who maintains this page

The material facts in the Pyrite 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.

Facts editor
June
Reviewer
Ralph
How facts are checked
Each fact is matched to the clause it cites; facts checked between 2026-09-22 and 2026-10-06
Last revised
2026-10-12
Purpose
Lets buyers and sellers check naming, disclosure and material facts clause by clause.

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