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Natural inorganic gem materials · Mineral group / supergroup · Natural identity; treatment status unknown

Garnet

The name of a mineral group among nesosilicates with many members; color cannot be inferred from this group name alone. 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 RalphReviewed by JuneLast updated 2026-10-12Who maintains this page

FAQCare and wear

Questions people ask about Garnet

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

Q1Why does garnet come in so many colours, and is there blue or colour-change garnet?

Garnet is a group of closely related mineral species, not a single species, and so it spans many colours.GIA Garnet DescriptionDifferences in chemical composition on an essentially shared crystal structure give colours from red, green and orange to pinkish orange, deep purplish red and even some blues.GIA Garnet DescriptionChina's national standard, by contrast, describes garnet as occurring in all colours except blue.GB/T 16553—2017A colour-change effect is recorded in garnet.GB/T 16553—2017

Q2How is a garnet confirmed as genuine rather than glass?

Garnet is isotropic, commonly with anomalous extinction.GB/T 16553—2017Its lustre is vitreous to subadamantine.GB/T 16553—2017In the mid-infrared it shows its own diagnostic band pattern.GB/T 16553—2017Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.What this page can answer

Q3What are the main types of garnet?

More than twenty garnet species exist, but only five are commercially important: pyrope, almandine, spessartine, grossular and andradite.GIA Garnet DescriptionThe group comprises an aluminium series and a calcium series, and substitution between them yields intermediate types, commonly hessonite, chrome-vanadium grossular, demantoid, carbuncle and hydrogrossular.GB/T 16553—2017All garnets share essentially the same crystal structure but vary in chemical composition.GIA Garnet Description

Q4Can you wear a garnet ring every day?

Yes, with care: garnet is Mohs 6.5 to 7.5 depending on type, with almandine, pyrope, spessartine and tsavorite harder and demantoid softer, and its fair to good toughness suits all jewellery, though it should be spared hard blows and rough wear.GIA Gem Encyclopedia (care guide)Prong and bezel settings are rated relatively safe, flush and channel call for caution and pavé for extreme caution.Gems & Gemology 1987 (Martin)Facet junctions can abrade if scraped.CIBJO Retailers' Reference Guide (2021)

Q5How should you clean garnet?

Warm soapy water is always safe; ultrasonic cleaning is usually fine except for fractured stones, and steam is not advised.GIA Gem Encyclopedia (care guide)The very few fracture-filled stones should be cleaned only with warm soapy water.GIA Gem Encyclopedia (care guide)It is stable to light and chemicals, though hydrofluoric acid can attack it.GIA Gem Encyclopedia (care guide)Thermal shock should be avoided, as it is likely to cause fractures.Gems & Gemology 1987 (Martin)

Q6How does garnet form?

Under the heat and pressure of metamorphism, suitable rock chemistry promotes the crystallization of garnet-group minerals.GIA Garnet DescriptionRed garnet is one of the commonest and most widely distributed gems, occurring in metamorphic rocks on every continent.GIA Garnet DescriptionGreen garnet such as tsavorite also forms in metamorphic rocks but is rarer, because it needs unusual rock chemistries and special conditions.GIA Garnet DescriptionThe sources give no absolute age or duration for garnet formation.GIA Garnet Description

Q7What makes a good-quality garnet?

According to GIA, garnet is a group of several minerals, so quality is judged by type.GIA Garnet Quality FactorsTypical clarity, for example, depends on the type: the red garnets almandine, pyrope and rhodolite usually have no eye-visible inclusions, while in demantoid the eye-visible 'horsetail' inclusions can raise its standing.GIA Garnet Quality Factors

Q8What does garnet symbolize, and does it have healing powers?

There is no scientific evidence that garnet 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)Its recorded cultural role is as the January birthstone: Jewelers of America and Japan's JJA list it for January, and the U.K. National Association of Jewellers lists it as traditional for January.Cultural recordsMuseum evidence places garnet beadwork and inlay back to at least the 20th–19th centuries BCE in Egypt, recurring in Etruscan, Hellenistic and Byzantine goldwork.The Met 26.7.1387 · The Met 22.1.243 +4

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

Rather than one mineral, garnet is a family of nesosilicates whose members keep nearly the same crystal framework while differing in chemistry, which is why garnet gems appear in almost all hues. The commonest and most widely distributed garnet is the red one, which is present on every continent in rocks recrystallised by heat and pressure. A green garnet, tsavorite, likewise develops in such metamorphic rocks, but it is scarcer because its formation demands uncommon rock compositions and particular conditions. Member species number more than twenty, yet just five matter commercially as gems: almandine, pyrope, spessartine, grossular and andradite.

Scope: Used to describe the overall formation environments and varietal composition of garnet as a mineral group; the formation conditions of specific sub-varieties (such as tsavorite) may be more restricted.

Sources GIA Garnet Description

Where it forms

Metamorphic rocks (altered by heat and pressure): the principal host of the common red garnets.

Sources GIA Garnet Description

Metamorphic rocks of unusual chemistry: green tsavorite requires unusual rock chemistry and special conditions.

Sources GIA Garnet Description

How it forms, step by step

  1. Under metamorphic conditions (heat and pressure), suitable bulk-rock chemistry promotes crystallization of garnet-group minerals.

    Sources GIA Garnet Description

  2. Because the group members share a similar structure, the lattice accommodates different elements, producing many colour varieties.

    Sources GIA Garnet Description

  3. Red (almandine-pyrope) garnets form widely in metamorphic rocks on every continent, whereas green tsavorite requires special chemistry and is rare.

    Sources GIA Garnet Description

Link to appearance

Chemical-composition differences give colours from red, green and orange to pinkish orange, deep purplish red and even some blues, on an essentially shared crystal structure.

Sources GIA Garnet Description

Timescale

The sources give no absolute age or duration for garnet formation.

Sources GIA Garnet Description

Supporting findings

Among gems, red garnet ranks as one of the commonest and most widely distributed, occurring on every continent in metamorphic rocks.

Evidence grade A

Scope: Concerns red garnets (almandine-pyrope); other colours differ in abundance.

Sources GIA Garnet Description

Green garnet such as tsavorite also occurs in metamorphic rocks but is rarer because it needs unusual rock chemistries and special conditions.

Evidence grade A

Scope: Uses tsavorite as the example; does not cover every green garnet species.

Sources GIA Garnet Description

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).

Africa

  • Africa (continent)Commercial source · Principal source · not on the maptoday Africa supplies much of the world’s garnet
    Sources GIA Birthstones

Asia

Europe

  • Bohemia, CzechiaHistorical source · Principal sourceprimary source of red pyrope in Victorian times
    Sources GIA Birthstones

South America

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.

Human use and museum objects

Museum evidence places the use of garnet as beadwork/inlay back to at least the 20th-19th centuries BCE in Egypt (Met 22.1.243), recurring in Etruscan (95.15.286), Hellenistic (74.51.3517) and Byzantine (Cleveland 1954.3) goldwork.

Evidence grade A

Scope: Applies to collection objects recorded as garnet (garnet group); the records do not distinguish individual garnet species.

Sources The Met 26.7.1387 · The Met 22.1.243 · The Met 15.3.327 +3

The Met holds Egyptian garnet necklaces of ca. 1580-1458 BCE (early New Kingdom; acc. 26.7.1387, Upper Egypt, Thebes) and of ca. 1981-1802 B.C. (acc. 22.1.243, garnet with carnelian and agate), among its earliest garnet objects, followed by a necklace of ca. 1802-1640 B.C. (acc. 15.3.327). In the Mediterranean and Near East, an Etruscan gold-and-garnet pin (acc. 95.15.286, possibly 5th-4th century BCE) and a Hellenistic gold earring with garnet beads (acc. 74.51.3517, 2nd century BCE) show garnet set into gold jewellery. A Byzantine gold-and-garnet necklace in the Cleveland Museum of Art (acc. 1954.3, 6th century CE) continues the tradition.

Sources The Met 26.7.1387 · The Met 22.1.243 · The Met 15.3.327 +3

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

2000 BCE1000 BCE01000Met 22.1.243ca. 1981–1802 B.C. probablyMet 15.3.327ca. 1802–1640 B.C.Met 26.7.1387ca. 1580–1458 BCEMet 95.15.286possibly 5th–4th century BCEMet 74.51.35172nd century BCECMA 1954.3500s
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 26.7.1387Necklace · ca. 1580–1458 BCE · Upper Egypt, ThebesGarnet
  • The Met 22.1.243Ball bead necklace · ca. 1981–1802 B.C. probablyGarnet, carnelian, agate
  • The Met 15.3.327Necklace · ca. 1802–1640 B.C. · Memphite RegionCarnelian, garnet, shell, amethyst
  • The Met 95.15.286Gold and garnet pin · possibly 5th–4th century BCE · EtruscanGold, garnet
  • The Met 74.51.3517Gold earring with woman's head and beryl and garnet beads · 2nd century BCE · GreekGold, beryl, garnet
  • Cleveland Museum of Art 1954.3Necklace with Pendants · 500s · Byzantium, Constantinople?, early Byzantine period, 6th centurygold, garnets

Cultural records for this material: Birthstone list.

Other research findings

All garnets share essentially the same crystal structure but vary in chemical composition; more than twenty species exist, only five commercially important (pyrope, almandine, spessartine, grossular, andradite).

Evidence grade A

Scope: Focuses on gem-commercial species; full mineralogical classification may be finer.

Sources GIA Garnet Description

Garnet is a group of closely related mineral species, not a single species, and hence spans many colours.

Evidence grade A

Scope: Defined as a mineral group/gem name; individual stones may be chemical mixtures of species.

Sources GIA Garnet Description

Garnet is a group of several minerals, so quality is judged by type. Typical clarity, for example, depends on the type: the red garnets almandine, pyrope and rhodolite usually have no eye-visible inclusions, while in demantoid the eye-visible 'horsetail' inclusions can raise its standing.

Evidence grade B

Scope: Quality factors as described by one educational source; not a grading standard and not a statement about the value of any piece.

Sources GIA Garnet Quality Factors

Limits of this research

  • Research status: Formation, occurrence or other material-specific findings found in authoritative sources
  • The source is a GIA encyclopedia entry; no formation temperature/pressure, age or deposit-specific data.
  • Green garnet is illustrated only by tsavorite; not all species covered.

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
Garnet

GB/T 16552—2017 Table A.1 “Garnet” · CIBJO Gemmological Laboratories Book 2024 §7.2.1.94 “Garnet”

Construction or treatment status

Natural identity; treatment status unknown

Treatments recorded for this material: Heated / Heat-treated, Filled / Fracture-filled

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

"Garnet" is a market name rather than a mineral species name; before using it, verify: Industry-wide term that does not denote a single species.

What this means for you

Before buying, check the recommended listing name "Garnet" 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

Trade-name ruling

  • Industry-wide term that does not denote a single species.
Suggested listing name
Garnet

Care and wear

Care

care (cleaning)3 sources compared

Garnet — care (cleaning): somewhat sensitive to heat (and some acids), so a soft, non-abrasive damp cloth is advised; facet junctions can abrade if scraped.

CIBJO Retailers' Reference Guide (2021)

Treatment state
any treatment state
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (cleaning): the very few stones that are fracture-filled should be cleaned only with warm soapy water.

GIA Gem Encyclopedia (care guide)

Treatment state
treated
Only after these treatments
filling
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (cleaning): Warm soapy water is always safe; ultrasonic is usually fine except for fractured stones; steam is not advised.

GIA Gem Encyclopedia (care guide)

Treatment state
any treatment state
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (cleaning): ultrasonic and steamer: use caution; note: ultrasonic is risky with liquid inclusions; avoid thermal shock.

Gems & Gemology 1987 (Martin)

Treatment state
untreated
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (chemicals): stable to light and chemicals, though hydrofluoric acid can attack it.

GIA Gem Encyclopedia (care guide)

Treatment state
any treatment state
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (wear): Mohs 6.5 to 7.5 depending on type (almandine, pyrope, spessartine and tsavorite on the harder side, demantoid softer); fair to good toughness makes it suitable for all jewellery, but spare it hard blows and rough wear.

GIA Gem Encyclopedia (care guide)

Treatment state
any treatment state
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (setting): prong and bezel: relatively safe; flush and channel: use caution; pavé: use extreme caution; note: heavily included stones (tsavorite especially) or those with liquid inclusions need extra care.

Gems & Gemology 1987 (Martin)

Treatment state
untreated
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — care (repair): polishing: relatively safe; pickle pot: use extreme caution; jeweller's torch and thermal shock: avoid; note: avoid thermal shock, which is likely to cause fractures.

Gems & Gemology 1987 (Martin)

Treatment state
untreated
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — 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
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

CleaningCleaning Garnet: GIA material states that, in any treatment state, warm soapy water is always safe, ultrasonic cleaning is usually safe except for fractured stones, and steam cleaning is not recommended; the very rare fracture-filled stones (treated, filling only) should be cleaned only with warm soapy water. Martin, Gem DurabilityMartin's Gemstone Durability: Design to Display states that, untreated, ultrasonic and steam cleaning call for caution, ultrasonic cleaning is risky for stones with fluid inclusions, thermal shock should be avoided, and heat, daylight and artificial light in display cases are relatively safe. CIBJOCIBJO material states that, in any treatment state, Garnet is somewhat sensitive to heat and certain acids, and cleaning with a soft, non-abrasive damp cloth is recommended. GIAGIA material states that, in any treatment state, Garnet is stable to light and chemicals but is attacked by hydrofluoric acid; at Mohs 6.5–7.5 depending on the species, it suits all kinds of jewellery, but should not take hard knocks or rough wear.

This table scrolls sideways on narrow screens.

QuestionMatching entries
Can it go in an ultrasonic or steam cleaner?somewhat sensitive to heat (and some acids), so a soft, non-abrasive damp cloth is advised; facet junctions can abrade if scraped; the very few stones that are fracture-filled should be cleaned only with warm soapy water; Warm soapy water is always safe; ultrasonic is usually fine except for fractured stones; steam is not advised; ultrasonic and steamer: use caution; note: ultrasonic is risky with liquid inclusions; avoid thermal shock
Heat and thermal shockpolishing: relatively safe; pickle pot: use extreme caution; jeweller's torch and thermal shock: avoid; note: avoid thermal shock, which is likely to cause fractures
Light and displayheat in the display case, sunlight and artificial light: relatively safe
Contact with acids, alkalis and household chemicalsstable to light and chemicals, though hydrofluoric acid can attack it
Wearing limits (knocks, settings)Mohs 6.5 to 7.5 depending on type (almandine, pyrope, spessartine and tsavorite on the harder side, demantoid softer); fair to good toughness makes it suitable for all jewellery, but spare it hard blows and rough wear; prong and bezel: relatively safe; flush and channel: use caution; pavé: use extreme caution; note: heavily included stones (tsavorite especially) or those with liquid inclusions need extra care

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.

any treatment state

untreated

treated (Only after these treatments: filling)

Durability and wearing

Toughness

Fair to good

Sources GIA Gem Encyclopedia (care guide)

Treatments and identification leads

Registered treatmentsThe treatments registered for Garnet are filling and heat treatment. Values not givenBoth have the status treated; stability and prevalence are both marked “—”, which in the register means the cited source gives no value, not “none”. Identification cluesIdentification leads for filling include: under a loupe, where the filler reaches the surface its lustre differs from the garnet itself, and flash effects and gas bubbles may appear at the filled spots; the infrared spectrum can detect the characteristic bands of the filler; and luminescence imaging (such as a UV fluorescence viewer) can show where the filler is distributed. The identification lead for heat treatment is that dark red garnet becomes lighter in colour when heated, and this is hard to detect.

This table scrolls sideways on narrow screens.

TreatmentMarket frequency (CIBJO)Stability (CIBJO)GB/T 16552 categoryJJA/AGL listingIdentification leads
fillingStatus: treated——Graded — see §5.4.1, Table 1—See identification leads
heatingStatus: treated——Optimization—See identification leads

Where each treatment acts (schematics): Filled / Fracture-filled · Heated / Heat-treated

“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16553—2017; GB/T 16552—2017 Table B.1

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 Garnet, the name register records "Garnet", for which no restriction on use as a name is recorded.

Standard and listing namesThe Chinese formal name for Garnet comes from GB/T 16552—2017 Table A.1; the English trade name/synonym is Garnet, the mineralogical name is written Garnet group (nesosilicates), and the suggested listing name is Garnet. Institution usageGIA and CIBJO wording is on record, both as Garnet; the FTC text on file has no wording for this name (checked); Gem-A is unchecked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe formal name of Japan's GSJ is given in Japanese, Germany (RAL) writes Granat, the EU writes Garnet and France (DGCCRF) writes Grenat. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Garnet) and Japanese. Trade and mineralogical namesThe English market name Garnet is registered by this site's own ruling, without a clause.

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)
GarnetEnglishmarket 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
Garnet (on record for GIA, CIBJO (GIA Gem Encyclopedia; CIBJO Gemmological Laboratories Book 2024 §7.2.1.94); no wording for this name in the FTC text on file; Gem-A unchecked — bodies without a recorded wording show the entry's own English name)
GSJ (Japan) formal name
ガーネット／柘榴石
Chinese formal name
石榴石 (GB/T 16552—2017 Table A.1)
Mineralogical name
Garnet group (nesosilicates)

Four-language names

简体中文
石榴石
繁體中文
石榴石
English
Garnet
日本語
ガーネット

National and regional formal names

Germany (RAL)
Granat
European Union
Garnet
France (DGCCRF)
Grenat

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

Classification

Origin
Natural materials
Material domain
Natural inorganic gem materials
Browsing family
Garnet-group minerals and gem varieties
Identity tier
Mineral group / supergroup
Mineral chemical class
Silicates
Construction or treatment status
Natural identity; treatment status unknown

Treatments listed by standards

For Garnet, GB/T 16552—2017 Annex B, Table B.1 lists heating and filling: heating improves colour and is categorised as an optimization; filling improves or changes durability and appearance, and its category is determined by grade. What Table B.1 is, and how its grades are defined, are on the Gem treatments page.

GB/T 16552-2017, Annex B, Table B.1

Table B.1, row “Garnet” (p.15):

This table scrolls sideways on narrow screens.

MethodEffectCategory
HeatingImproves colourOptimization
FillingImproves or changes durability and appearanceGraded — see §5.4.1, Table 1

What Table B.1 is, and how the “see 5.4.1” grades are defined: see the GB/T 16552: optimization vs treatment page.

What it is and how it's identified

The material facts for Garnet include: the composition falls into an aluminium series and a calcium series, with transitional sub-species between the two arising from isomorphous substitution; the structure is crystalline and cubic, with crystal forms of rhombic dodecahedra or trapezohedra, or combinations of the two. Mohs hardness is 7–8, and this site notes that hardness alone is not enough to judge durability; there is no cleavage; density is 3.5–4.3 g/cm³, and this site notes that the clause has further sub-grades and the overall value is used. The optic character is isotropic, commonly with anomalous extinction; there is no birefringence. The refractive index is given by series: 1.734–1.94 for the calcium series (grossular–andradite–uvarovite) and 1.71–1.83 for the aluminium series (pyrope–almandine–spessartine). Untreated Garnet has a vitreous to subadamantine lustre. As optical effects, asterism is visible but rare, generally as four-rayed stars and occasionally as six-rayed stars (almandine), and the colour-change effect can be seen.

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”.

Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Garnet (how to read class-level values).

Definition

Garnet — composition (chemistry): two series — aluminum series spanning Mg3Al2(SiO4)3, Fe3Al2(SiO4)3 and Mn3Al2(SiO4)3; calcium series spanning Ca3Al2(SiO4)3, Ca3Fe2(SiO4)3 and Ca3Cr2(SiO4)3.

GB/T 16553—2017

Does this standard apply
applies to this entry
Source & check 2026-09-22
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-22)
Fact checked on
2026-09-22

Garnet — composition (phase): The garnet group comprises an aluminium series and a calcium series; isomorphous substitution between them yields intermediate subspecies, commonly hessonite, chrome-vanadium grossular, demantoid, carbuncle and hydrogrossular.

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): §5.1.15 Additional notes (locator checked 2026-09-28)
Fact checked on
2026-09-21

Structure

Garnet — 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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — structure (crystal system): cubic

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — structure (crystal habit): rhombic dodecahedra, tetragonal trisoctahedra, or crystals combining the two forms.

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Durability

Garnet — Mohs hardness: 7–8

GB/T 16553—2017

123456789107–8References (diamond = value, bar = range; below)

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))

Mohs hardnessSource: GB/T 16553—2017
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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — cleavage: none

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Physical properties

Garnet — density: 3.5–4.3 g/cm³

GB/T 16553—2017

0.51.52.53.54.55.56.57.53.5–4.3
Specific gravitySource: 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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Optical

Optical effects on record: asterismrepresentative example: cause in Star Sapphire (schematic)colour change

Garnet — optic character: isotropic, commonly with anomalous extinction

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — refractive index: 1.734–1.94

GB/T 16553—2017

1.31.72.12.52.93.31.734–1.94
Refractive indexSource: GB/T 16553—2017
Does this standard apply
applies to this entry
What this covers
garnet, calcium series (grossular–andradite–uvarovite)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Refractive index · Calcic series (locator checked 2026-09-28)
Fact checked on
2026-09-26

Garnet — refractive index: 1.71–1.83

GB/T 16553—2017

1.31.72.12.52.93.31.71–1.83
Refractive indexSource: GB/T 16553—2017
Does this standard apply
applies to this entry
What this covers
garnet, aluminium series (pyrope–almandine–spessartine)
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 Refractive index · Aluminous series (locator checked 2026-09-28)
Fact checked on
2026-09-26

Garnet — birefringence: none

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — pleochroism: 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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — fluorescence (overall): generally none; grossular: may have weak, orange-yellow.

GB/T 16553—2017

UV fluorescencemay have: orange-yellowweak, grossularDots are illustrative colours built from the colour names, not measured values

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — spectrum (UV-visible): pyrope: 564 nm broad absorption band; 505 nm absorption peak; iron-bearing ones: may have 440 nm absorption peak; may have 445 nm absorption peak; fine pyrope: may have chromium absorption (red region); almandine: 504 nm strong absorption band; 520 nm strong absorption band; 573 nm strong absorption band; 423 nm weak absorption band; 460 nm weak absorption band; 610 nm weak absorption band; 680~690 nm weak absorption band; spessartine: 410 nm absorption peak; 420 nm absorption peak; 430 nm absorption peak; 460 nm absorption band; 480 nm absorption band; 520 nm absorption band; may sometimes have 504 nm absorption peak; may sometimes have 573 nm absorption peak; iron-coloured hessonite: may have 407 nm absorption band; may have 430 nm absorption band; andradite and demantoid: 440 nm absorption band; may have 618 nm absorption peak; may have 634 nm absorption peak; may have 685 nm absorption peak; may have 690 nm absorption peak; melanite: 505 nm strong absorption band; 576 nm weak absorption band; 527 nm weak absorption band; uvarovite: unknown.

GB/T 16553—2017

400450500550600650700 nmpyrope505564iron-bearing ones440445almandine423460504520573610680–690spessartine410420430460480504520573iron-coloured hessonite407430andradite and demantoid440618634685690melanite505527576
Absorption spectrum (schematic)Line = absorption peak; hatching = absorption band; heavier or darker = higher recorded strength grade (not a measured intensity); Schematic: positions and strength grades as given by the cited source, not a measured curveSource: 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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — spectrum (infrared): In the mid-IR, garnet's own diagnostic band pattern appears.

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — optical effect (asterism): seen; rare; generally a four-pointed star; occasionally a six-rayed star (almandine).

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — optical effect (colour change): 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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — magnification: gas-liquid inclusions, mineral inclusions, needle inclusions, rounded or irregular included crystals, radiation haloes around zircon, horsetail inclusions in andradite.

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): §5.1.15 (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — body colour: all colours except blue. Pyrope: medium to dark; orange-red, red. Almandine: orange-red to red, purplish red to reddish purple, darker in tone. Spessartine: orange to orange-red. Grossular: light to dark green, light to dark yellow, orange-red; rarely colourless.

Andradite (demantoid included): yellow, green, brownish black. Melanite: grey to black. Uvarovite: green.

GB/T 16553—2017

Treatment state
untreated
Does this standard apply
applies to this entry
Qualification

GB/T 16553—2017 sums up the colour of Garnet as “all colours except blue”; in its chapter 5, Tourmaline, Calcite, Opal and other variety clauses likewise say “all colours” or “all body colours”.

General note
colour alone is not identity
Source & check 2026-09-26
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (locator checked 2026-09-26)
Fact checked on
2026-09-26
CIBJO definitions
asterism, colour change

Quality factors

Garnet — quality factor (lustre): vitreous to subadamantine

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): §5.1.15 (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.

1.81.853.73.83.944.14.2Refractive indexSpecific gravity12345Garnet

This material (RI / SG midpoints): 1.825 / 3.9; Closest values: 1Spessartine 1.802 / 3.9, 2Uvarovite 1.85 / 3.9, 3Almandine 1.79 / 3.9, 4Andradite 1.875 / 3.9, 5Burma Ruby 1.768 / 4

Show the full chart (330 registered materials)1.41.51.61.71.81.922.12.22.32.41234567Refractive indexSpecific gravity12345Garnet

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

Refractive index × specific gravity (all registered materials)Each dot is one material's registered refractive index and specific gravity (range midpoints, not measurements); gold = this material, dark = the nearest few (picked on this site by distance in RI ÷ 0.02 and SG ÷ 0.1, leaving out near-identical varieties of the same species)Source: each material's registered refractive index and specific gravity facts (GB/T 16553 and others; sources on each entry)

Testing and market

After filling, Garnet can be identified by several leads: under magnification the exposed filler has a lustre different from the garnet host, and filled areas may show a flash effect and gas bubbles; infrared spectroscopy can detect the filler's characteristic bands; luminescence imaging (for example a UV fluorescence viewer) can show where the filler lies. In heated Garnet, dark red stones become lighter on heating, and this is hard to detect. The leads for filling and heating come from GB/T 16553—2017, which can be followed for Garnet as a reference only and does not govern it directly. The laboratory protocol in the CIBJO Gemmological Laboratories Book 2024 requires a focused check for heating (demantoid), with a note on testing methods: the special optical effects are colour change and asterism, and refractive index may exceed the upper limit of the refractometer.

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: §6.1.38.

How far testing can go

Garnet that has undergone filling can be identified by the following features: Under magnification the exposed part of the filler has a surface luster differing from that of the host stone, and the filled area may show a flash effect and gas bubbles; infrared spectra show characteristic absorption bands of the filler; luminescence imaging (such as a UV fluorescence viewer) shows how the filler is distributed.

GB/T 16553—2017

Treatment state
treated
Does this standard apply
can be followed as a reference only
Treatment
filling
Source & check 2026-09-21
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (filling) (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet that has undergone heating can be identified by the following features: Heating dark red garnet lightens the colour. Hard to detect.

GB/T 16553—2017

Treatment state
treated
Does this standard apply
can be followed as a reference only
Treatment
heating
Source & check 2026-09-21
Source
  • GB/T 16553—2017 Gems — Testing (GB/T): §5.1.15 (heating) (locator checked 2026-09-21)
Fact checked on
2026-09-21

Garnet — what the CIBJO laboratory protocol says to watch for: heat treatment (demantoid)

CIBJO Gemmological Laboratories Book 2024

Treatment state
any treatment state
Source & check 2026-09-26
Source
Fact checked on
2026-09-26

Garnet — notes on test methods in the CIBJO laboratory protocol:

CIBJO laboratory protocol, in its own order; only the notes registered on this site
Test methodWhat the protocol notes for it
Phenomena: Colour-change, star;
Refractometer (refractive index): May be outside upper range

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

This table scrolls sideways on narrow screens.

TermClauseDefinitionCross-check
Garnet7.2.1.94see almandine, pyrope, rhodolite, grossular, hessonite, tsavorite, spessartine, mandarin garnet, andradite, demantoid, melanite, topazolite, Malaya garnet, umbalite, Mali garnet, uvaroviteDefined directly by CIBJO; also present in the GB/T annex.

Evidence and sources

Authority basis and clause sources

GB/T 16552—2017
Listed Table A.1 “Garnet” · Source
CIBJO Gemmological Laboratories Book 2024
Listed §7.2.1.94 “Garnet” · Source

Sources

Further reading

Related pages

Treatments recorded for this material

Recorded cultural contexts

Birthstone list

The U.S. Jewelers of America roster lists Garnet for January; the U.K. National Association of Jewellers chart lists Garnet as traditional for January; and Japan's JJA 2021 revised roster lists Garnet for January. This records trade-association convention only; it does not establish material identity, natural origin, treatment, provenance, or effect.

Relation
Industry list inclusion

This table scrolls sideways on narrow screens.

Publisher or holderRegionFrom / periodSource and locator
Jewelers of AmericaUnited States1912 to the presentJewelers of America, “Birthstone Jewelry” (web page, consulted 2026-08-22)
Birthstone roster table, January row: Garnet
Japan Jewellery AssociationJapanfrom 20 December 2021Tanjoseki (Japanese birthstone roster, Japan Jewellery Association page; revision of 20 December 2021)
2021 revised birthstone roster, January row: Garnet
National Association of JewellersUnited Kingdom—National Association of Jewellers, “Zodiac Birthstones Jewellery: Star Signs, Gemstones and Their Meaning” (web page, consulted 2026-08-22)
Zodiac birthstone chart, January row: Garnet (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.

Related-entry tree for Garnet on this site: 10 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Garnet) is marked.

This table scrolls sideways on narrow screens.

PageContentStatus
Browsing familyGarnet-group minerals and gem varietiesLive
Treatments recorded for this materialHeated / Heat-treated, Filled / Fracture-filledLive
Related articlesTo be added (placeholder)Planned

Who maintains this page

The material facts in the Garnet 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
Ralph
Reviewer
June
How facts are checked
Each fact is matched to the clause it cites; facts checked between 2026-09-21 and 2026-09-26
Last revised
2026-10-12
Purpose
Lets buyers and sellers check naming, disclosure and material facts clause by clause.

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