On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral / gemstone variety · Natural identity; treatment status unknown
Peridot
Also known asChrysolite · Forsterite (conditional name) · Olivine (conditional name)
The name of the gem-quality, usually magnesium-rich variety in the olivine group, with the composition (Mg,Fe)2SiO4; it is not itself a mineral species name. 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 Peridot 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 PeridotHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Peridot3 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing PeridotCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of PeridotEach value with its source and check date
- Peridot in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name, names in national standards; 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 PeridotWhere the name comes from; how people have used it, with museum objects
- Listing and disclosing PeridotThe listing name to use; what must be disclosed before sale
- Standard clauses that define PeridotWhich 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
Olivine is a mafic silicate species with the formula (Mg,Fe)2SiO4 that belongs to the olivine group; gem-quality material is normally its Mg-rich end member forsterite. Peridot appears as nodules hosted by igneous rocks and, more rarely, as crystals in veins (Myanmar, Pakistan) or inside meteorites; its principal sources are peridotite xenoliths in alkaline basalts, together with serpentinized dunites. The Central Highlands peridot of Vietnam came from a spinel lherzolite source; it formed at roughly 910–980°C, at a pressure assumed to be 2.0 ± 0.5 GPa, which corresponds to a depth near 60 km. The record's species name is olivine, while peridot is the gem-grade variety name.
Scope: Covers the origin, composition and occurrence of olivine (gem-quality material being magnesium-rich forsterite) as a mantle-derived mineral species, and explains that peridot is a gem variety name; does not address synthetic or imitation materials.
Sources G&G Fall 2016 · Handbook of Mineralogy
Where it forms
Xenoliths (nodules) of peridotite carried in alkaline basalts
Sources G&G Fall 2016
Dunites that have been serpentinized
Sources G&G Fall 2016
A mantle spinel lherzolite source region (about 60 km deep)
Sources G&G Fall 2016
Mafic and ultramafic igneous rocks and thermally metamorphosed impure dolomitic limestones; also in meteorites
Sources G&G Fall 2016
How it forms, step by step
A mantle source (spinel lherzolite) equilibrates at about 910–980°C and ~2.0 GPa, crystallizing Mg-rich olivine.
Host alkaline basaltic magma ascends, carrying peridotite nodules/xenoliths to the surface.
Peridot occurs as nodules, or after weathering and erosion it concentrates in placer deposits (e.g. the alluvial gravels of Vietnam).
Olivine also forms in mafic/ultramafic igneous rocks and thermally metamorphosed impure dolomitic limestones, and occurs as crystals in meteorites.
Link to appearance
Peridot ranges from light yellowish green to darker yellow-green, olive green and brownish green, with a vitreous luster and transparent to translucent clarity. Its colour is mainly caused by iron (Fe2+) in the lattice: Fe2+ absorption features dominate the UV-Vis-NIR spectra, confirming iron's leading role in the colour.
Sources G&G Fall 2016
Timescale
The sources give no absolute geological age for olivine formation; they give only formation temperature (910–980°C) and pressure (~2.0 GPa) conditions.
Sources G&G Fall 2016
Supporting findings
Peridot occurs as nodules hosted by igneous rocks and, more rarely, as crystals in veins or within meteorites; its principal sources are xenoliths of peridotite carried in alkaline basalts, together with serpentinized dunites.
Evidence grade AScope: Describes peridot's general modes of occurrence; it does not infer the locality of any sample.
The Central Highlands peridot of Vietnam came from a spinel lherzolite source; it formed at roughly 910–980°C, at a pressure assumed to be 2.0 ± 0.5 GPa, which corresponds to a depth near 60 km.
Evidence grade AScope: A P-T estimate for the Vietnamese locality; it does not extrapolate to peridot from other sources.
Peridot occurs as ultramafic nodules 5–40 cm across within alkaline basalts, and forsterite contents of the samples range from 90.6 to 91.3 mol.%.
Evidence grade AScope: Describes the size and compositional range of peridot-bearing nodules; based on the studied samples.
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Zabargad Island, EgyptRed Sea island; vein crystals
Sources GIA Gem Encyclopedia
Asia
- ChinaNodules in basalt lava flows
Sources GIA Gem Encyclopedia
- VietnamNodules in basalt lava flows
Sources GIA Gem Encyclopedia
- Sappat, Kohistan, Khyber Pakhtunkhwa, Pakistan
Sources GIA Gem Encyclopedia
- MyanmarVein or pocket crystals
Sources GIA Gem Encyclopedia
Europe
- FinlandLarge vein or pocket crystals, described as very rare
Sources GIA Gem Encyclopedia
North America
- Peridot Mesa, San Carlos Apache Reservation, Arizona, United States
Sources GIA Gem Encyclopedia
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
Iron (Fe2+) is chiefly responsible for peridot's colour; Fe2+ absorption features dominate its UV-Vis-NIR spectra, which confirms the main role of iron in the colour.
Evidence grade AScope: Describes peridot's chromophore; it refers to the general mechanism for gem peridot.
Where the name comes from
The etymology these sources give for olivine (peridot, gem-quality olivine) is that of the name forsterite — which honours the English mineral dealer and collector Adolarius Jacob Forster (1739–1806); no etymology is given by this source for the name "olivine/peridot" itself.
Evidence grade BScope: 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
The collection evidence shows the earliest datable peridot in Roman ring stones (Met 81.6.65, 81.6.120, ca. 1st century BCE-3rd century CE) and a lump from Egypt (Met 10.130.2838), with modern examples in American jewellery of about 1900-1910 (Met 2001.238, 2021.14.36). The evidence is limited and does not establish widespread or continuous ancient use.
Evidence grade AScope: Applies to collection objects recorded as peridot — Roman ring stones, an Egyptian lump and modern American jewellery; the evidence is limited.
Sources The Met 81.6.65 · The Met 81.6.120 · The Met 10.130.2838 +2
Only a small number of objects recorded as peridot are present. The earlier ones are a pair of Roman ring stones: Met 81.6.65 (1st century BCE-2nd century CE) and Met 81.6.120 (ca. 1st century BCE-3rd century CE), together with a lump of peridot from Egypt (Met 10.130.2838, ca. 1st-6th century CE). More recent examples are a gold brooch of about 1900 (Met 2001.238; gold, peridot, diamonds, pearls, enamel) and a pendant of about 1910 (Met 2021.14.36; gold, opals, peridot). The collection evidence is limited and concentrated at two ends — Roman and early 20th century — and does not establish continuous or widespread use in between or across regions.
Sources The Met 81.6.65 · The Met 81.6.120 · The Met 10.130.2838 +2
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
- The Met 81.6.65Peridot
- The Met 81.6.120Peridot
- The Met 10.130.2838Peridot
- The Met 2001.238Gold, peridot, diamonds, pearls, and enamel
- The Met 2021.14.36Gold, opals, peridot
Cultural records for this material: Birthstone list.
Other research findings
Olivine belongs to the olivine group and its Mg-rich end member is forsterite (Mg2SiO4); it is trimorphous with ringwoodite and wadsleyite and forms series with fayalite and with tephroite.
Evidence grade BScope: Describes the olivine group composition and end-member relations; not the exact Fo value of any specimen.
Sources Handbook of Mineralogy
The record name is the mineral species olivine; peridot is the yellowish green to green gem variety name of olivine, and the variety name is not an independent mineral species.
Evidence grade AScope: Defines the peridot-to-olivine variety-name-to-species relationship; it does not treat a gem-variety name as an independent species.
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The sources state no absolute geological age for olivine formation.
- The forsterite content (Fo90.6–91.3) is an observation on Vietnamese samples and does not represent all gem peridot.
- The record name is the mineral species olivine; peridot is the gem variety name, a variety-to-species relationship within the same mineral species.
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
- Peridot
GB/T 16552—2017 Table A.1 “Peridot” · CIBJO Gemmological Laboratories Book 2024 §7.2.1.173 “Peridot”
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
Peridot is Peridot: gem-quality, normally forsterite-rich olivine ((Mg,Fe)2SiO4); use "Peridot" for listings, and disclose any known treatments.
Evidence
- CIBJO · 7.2.1.173
What this means for you
Before buying, check the recommended listing name "Peridot" 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
care (cleaning)2 sources compared
Peridot — care (cleaning): ultrasonic: use caution; steamer: avoid.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Peridot row, CLEANING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (cleaning): Warm soapy water is best; ultrasonic and steam cleaners are not advised.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Peridot Care and Cleaning Guide: Section “Cleaning” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
care (heat)2 sources compared
Peridot — care (heat): Some stones are prone to damage due to thermal shock. Do not expose them to extreme temperature changes.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code e
- 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, Peridot, p.62; §6.2 e (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Peridot — care (heat): Rapid or uneven heating can fracture it
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Peridot Care and Cleaning Guide: Section “Stability” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
care (chemicals)2 sources compared
Peridot — care (chemicals): Treatments with dye, oil, resin, wax or plastic are not permanent; keep it away from all solvents (including dish-washing liquids), chemicals and heat.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code k
- Treatment state
- treated
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Peridot, p.62; §6.2 k (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Peridot — 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, Peridot, p.62; §6.2 h (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Peridot — care (chemicals): stable in light; sulfuric acid attacks it readily and hydrochloric acid less so, and acidic sweat can etch it over long periods.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Peridot Care and Cleaning Guide: Section “Stability” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (wear): Mohs 6.5 to 7 with fair to good toughness: wearable, but avoid scratches and hard blows that could fracture it.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Peridot Care and Cleaning Guide: Section “Hardness and toughness” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (special care): normal care
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XIII, Gemstone Information Chart, Peridot N, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (setting): bezel: relatively safe; prong: use caution; channel: use extreme caution; flush and pavé: avoid; note: consider the inclusions; facet edges chip easily.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Peridot row, SETTING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (repair): polishing: use caution; jeweller's torch, pickle pot and thermal shock: avoid.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Peridot row, REPAIR column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — care (display): heat in the display case, sunlight and artificial light: relatively safe.
Gems & Gemology 1987 (Martin)
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- Martin, “Gemstone Durability: Design to Display”, Gems & Gemology, Summer 1987: pp.66–67 fold-out chart, Peridot row, DISPLAY column (locator checked 2026-09-26)
- 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.
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.
Care entries by treatment state
The same entries grouped by the treatment state each applies to; each links to its full wording and source. Letters are CIBJO special-care codes, explained on the gemstone care page.
untreated
- ultrasonic: use caution; steamer: avoid
- normal care
- bezel: relatively safe; prong: use caution; channel: use extreme caution; flush and pavé: avoid; note: consider the inclusions; facet edges chip easily
- polishing: use caution; jeweller's torch, pickle pot and thermal shock: avoid
- heat in the display case, sunlight and artificial light: relatively safe
any treatment state
- Warm soapy water is best; ultrasonic and steam cleaners are not advised
- care (heat) §6.2 e
- Rapid or uneven heating can fracture it
- care (chemicals) §6.2 h
- stable in light; sulfuric acid attacks it readily and hydrochloric acid less so, and acidic sweat can etch it over long periods
- Mohs 6.5 to 7 with fair to good toughness: wearable, but avoid scratches and hard blows that could fracture it
treated
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.
Toughness
Fair to good toughness
Cleavage
{010}, {100}, imperfect
Treatments and identification leads
Registered treatmentsThe registered treatments for Peridot are filling, resin fracture filling and oil fracture filling. Stability and frequencyAll three have the status treated, stability unstable and prevalence rare. Values not givenThe identification leads and source are all marked “—”, which means the cited source gives no value, not “none”. SyntheticsAmong the identification facts, it is also registered that there is no synthetic Peridot on the market.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| fillingStatus: treated | rarely | unstable | — | — | — |
| fissure filling with resinStatus: treated | rarely | unstable | — | — | — |
| fissure filling with oilStatus: treated | rarely | unstable | — | — | — |
Where each treatment acts (schematics): Filled / Fracture-filled
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022; JJA/AGL 2025
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
Besides Peridot, the name register records "Chrysolite", "Forsterite" and "Olivine", for which no restriction on use as a name is recorded (CIBJO Gemmological Laboratories Book 2024 §7.2.1.91 “Forsterite”; CIBJO Gemmological Laboratories Book 2024 §7.2.1.159 “Olivine”; JJA/AGL Gemstone Nomenclature 2025 p.9); one further name in a non-Latin script is listed in the name register below (1 with no restriction recorded on use as a name).
Recommended listing nameThe suggested listing name for Peridot is Peridot; its Chinese formal name comes from GB/T 16552—2017 Table A.1, and the mineralogical name corresponds to Peridot. Names in four languagesThe four-language names are the Simplified and Traditional Chinese names, English Peridot and the Japanese names, the Japanese form also being the GSJ (Japan) formal name. Trade and mineralogical namesAmong trade names and synonyms, Chrysolite is a historical name. Candidate search termsForsterite, Olivine and a Japanese transliteration of olivine are search candidates only on this site, Forsterite and Olivine being based on the CIBJO Gemmological Laboratories Book 2024, and Olivine and its Japanese transliteration also appearing in the JJA/AGL Gemstone Nomenclature 2025. Institution usageFor authority wording, GIA and CIBJO record Peridot; the FTC text on file has no wording for this name, which has been checked; Gem-A is unchecked, and bodies without a recorded wording show the entry's own English name, which does not represent their position. National standard namesAmong national and regional formal names, Germany (RAL) and the European Union both use Peridot, and France (DGCCRF) Péridot.
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 (4) | ||||
| ChrysoliteEnglish | historical name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
| ForsteriteEnglish | synonym | search candidate only | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.91 “Forsterite” |
| OlivineEnglish | synonym | search candidate only | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.159 “Olivine”; JJA/AGL Gemstone Nomenclature 2025 p.9 |
| オリビンJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.9 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- ペリドット／橄欖石
- Chinese formal name
- 橄榄石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Peridot: gem-quality, normally forsterite-rich olivine ((Mg,Fe)2SiO4)
- Trade names and synonyms
- Chrysolite (historical name) · Forsterite (synonym; conditional name) · Olivine (synonym; conditional name)
Four-language names
- 简体中文
- 橄榄石
- 繁體中文
- 橄欖石
- English
- Peridot
- 日本語
- ペリドット／橄欖石
National and regional formal names
- Germany (RAL)
- Peridot
- European Union
- Peridot
- France (DGCCRF)
- Péridot
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Other silicate minerals
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
In the table of principal gem names in the November 2025 revision of the JJA/AGL (Japan) definitions and nomenclature of gems and ornamental materials, Peridot is recorded with the gem name Peridot, the species name Olivine and the colour yellowish green, and the table lists an untreated tier; the source is p.9 of that table. For how to read the JJA/AGL table, see this site's Gem treatments page.
JJA/AGL (Japan) table of principal gem names, 2025
This table scrolls sideways on narrow screens.
| Gem name | Species | Colour | Listed in the table | Notes |
|---|---|---|---|---|
| Peridot | Olivine | yellowish green | an untreated tier is listed |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.9
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
The composition of Peridot is registered as (Mg,Fe)2SiO4; structure crystalline, orthorhombic, with a prismatic or short prismatic habit, mostly as irregular grains. Mohs hardness 6.5–7; the site note explains that hardness alone is not enough to judge durability. Density 3.27–3.48 g/cm³, derived from the cited clause value 3.34 and its permitted tolerance of +0.14/−0.07. Optical character anisotropic, biaxial, positive or negative; refractive index 1.634–1.71, derived from the cited clause value 1.654–1.690 and its permitted tolerance of ±0.020; birefringence 0.035–0.038, where this site uses the overall clause value and the clause has finer sub-ranges. Untreated, pleochroism is weak, in green and yellowish green; luminescence is none; magnification shows disc-like gas-liquid inclusions, mineral inclusions, negative crystals and obvious doubling (birefringence); lustre is vitreous. The UV-visible spectrum has strong absorption bands at 453 nm, 477 nm and 497 nm; there are infrared absorption bands characteristic of peridot in the mid-infrared region; the cat's-eye effect can occur but is rare, and asterism can occur.
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
Peridot — composition (chemistry): (Mg,Fe) 2SiO4
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Structure
Peridot — structure (overall): crystalline
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — structure (crystal system): orthorhombic
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — structure (crystal habit): prismatic or stubby prisms, usually irregular grains.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Peridot — Mohs hardness: 6.5–7
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
- General note
- hardness only, not durability
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
For Peridot, the stability of filling is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- filling
- Qualification
This says how well the treatment holds up, not how durable Peridot itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Peridot, the stability of fissure filling with resin is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with resin
- Qualification
This says how well the treatment holds up, not how durable Peridot itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Peridot, the stability of fissure filling with oil is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with oil
- Qualification
This says how well the treatment holds up, not how durable Peridot itself is.
- General note
- no durability verdict here
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Physical properties
Peridot — density: 3.27–3.48 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 3.34, with a stated tolerance of +0.14 / -0.07. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Peridot — optic character: biaxial and anisotropic; optic sign may be either positive or negative.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — refractive index: 1.634–1.71
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.654–1.690, with a stated tolerance of ±0.020. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — birefringence: 0.035–0.038
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — pleochroism: weak, green and yellow-green
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — fluorescence (overall): none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — spectrum (UV-visible): 453 nm strong absorption band; 477 nm strong absorption band; 497 nm strong absorption band.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — spectrum (infrared): Peridot's own diagnostic bands are seen in the mid-IR
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — optical effect (chatoyancy): seen; rare
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — optical effect (asterism): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Peridot — magnification: disc gas-liquid inclusion, mineral inclusions, negative crystals, obvious birefringence.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
body colour2 sources compared
Peridot — body colour: yellow-green, green, brownish-green, etc.
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 Epidote, Sinhalite, Chrysoberyl and other variety clauses also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Peridot — body colour: Greenish yellow to yellowish (or brownish) green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Chrysoberyl, Andalusite, Andradite and other entries also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
How the sources relate
- GB/T 16553—2017 and CIBJO Gemmological Laboratories Book 2024
The two entries agree: yellowish green to green, and brownish green (the CIBJO Gemmological Laboratories Book gives greenish yellow to yellowish or brownish green).
- CIBJO definitions
- chatoyancy, asterism
Quality factors
Peridot — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.14 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
This material (RI / SG midpoints): 1.672 / 3.38; Closest values: 1Fei Cui / Jadeite Jade 1.683 / 3.35, 2Kornerupine 1.673 / 3.31, 3Synthetic Jadeite 1.66 / 3.34, 4Axinite 1.683 / 3.31, 5Sinhalite 1.688 / 3.48
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
Testing and market
Peridot: there is no synthetic peridot on the market. One risk that CIBJO's laboratory rules call for particular checks on in peridot is possible acid damage. Among peridot in circulation, filling, fissure filling with resin and fissure filling with oil are all rare. Which tests CIBJO's laboratory rules require for peridot, and what each method means, are defined in the rules 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: §6.1.58.
How far testing can go
Peridot — 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 Peridot in trade, the reported frequency of filling is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- filling
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Peridot in trade, the reported frequency of fissure filling with resin is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with resin
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Peridot in trade, the reported frequency of fissure filling with oil is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- fissure filling with oil
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Peridot — what the CIBJO laboratory protocol says to watch for: may be damaged by acids
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
Clause-level definitions for Peridot in CIBJO Gemmological Laboratories Book 2024 are recorded under the terms Forsterite, Olivine and Peridot. The Peridot entry gives the mineral group olivine, the mineral species forsterite and the mineral/gem variety peridot, noting that the CIBJO wording is quoted in full under Clause-level definitions on this page. Forsterite is defined as colourless to green, transparent to translucent, see also peridot; the Olivine entry points to peridot. On the Peridot entry's terms, olivine and forsterite are the mineral group and the mineral species, broader names, while this material corresponds to the mineral/gem variety peridot. The cross-check shows they are defined directly by CIBJO; the Peridot entry also appears in this edition of the GB/T annex, while no identically named English entry was found there for Forsterite or Olivine.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Forsterite | 7.2.1.91 | Colourless to green; transparent to translucent; see also peridot | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Olivine | 7.2.1.159 | see peridot | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Peridot | 7.2.1.173 | Greenish yellow to yellowish (or brownish) green variety of forsterite | Defined directly by CIBJO; also present in the GB/T annex. |
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.
- GIA – Gemological Institute of America (United States). Gem Encyclopedia: Peridot Description.
- 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
Recorded cultural contexts
The U.S. Jewelers of America roster lists Peridot for August; the U.K. National Association of Jewellers chart lists Peridot as traditional for August; and Japan's JJA 2021 revised roster lists Peridot for August. This records trade-association convention only; it does not establish material identity, natural origin, treatment, provenance, or effect.
This table scrolls sideways on narrow screens.
| Publisher or holder | Region | From / period | Source and locator |
|---|---|---|---|
| Jewelers of America | United States | 1912 to the present | Jewelers of America, “Birthstone Jewelry” (web page, consulted 2026-08-22) Birthstone roster table, August row: Peridot |
| Japan Jewellery Association | Japan | from 20 December 2021 | Tanjoseki (Japanese birthstone roster, Japan Jewellery Association page; revision of 20 December 2021) 2021 revised birthstone roster, August row: Peridot |
| National Association of Jewellers | United Kingdom | — | National Association of Jewellers, “Zodiac Birthstones Jewellery: Star Signs, Gemstones and Their Meaning” (web page, consulted 2026-08-22) Zodiac birthstone chart, August row: Peridot (Traditional) |
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 | Other silicate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Peridot 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.