On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural; treatment common (require certificate to distinguish)
Turquoise
Also known asSpider's Web Turquoise · Turquoise Matrix
A hydrous copper aluminium phosphate mineral species; filling, dyeing and stabilisation treatments are extremely common, and reconstructed material must carry the prefix "reconstructed" before its 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.
Questions people ask about Turquoise
Every sentence below is followed by the registered fact it rests on; answers add no new facts and promise no outcome.
Q1How can you tell real turquoise from dyed howlite and other fakes?
Turquoise is often imitated with dyed howlite or magnesite, and infrared (FTIR) spectra clearly separate turquoise from these imitations.G&G Winter 2024Plastic and ceramic imitations exist too, including one Gilson introduced in the early 1970s.GIA Introduction to Imitation GemsUnder magnification, dyed turquoise shows colour concentrated in fissures, between grains or in surface hollows, and its UV-visible spectrum differs from natural material.GB/T 16553—2017Laboratories are told to watch for impregnation, dye, composites, imitation matrix and synthetics.CIBJO Gemmological Laboratories Book 2024Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.What this page can answer
Q2What is stabilized turquoise?
It is lower-quality turquoise bonded together at the granular level with polymer resins to make it more stable; FTIR spectra reveal the resins even when they are hard to see under a microscope.G&G Winter 2024A Gems & Gemology note states that turquoise is usually impregnated with acrylic polymer or epoxy resin for stabilization.G&G Fall 2015Impregnation with plastic is reported as common in the trade.CIBJO Gemstone Book 2022Plastic-impregnated turquoise needs special care: avoid hot water and household chemicals.AGTA Gemstone Information Manual, 17th ed.
Q3Why does turquoise change colour or turn green?
Turquoise is porous, so skin oils, lotions and the like can discolour it as it is handled.Gems & Gemology 1987 (Martin)Chemicals, cosmetics and even sweat can discolour it, and it dissolves slowly in hydrochloric acid.GIA Gem Encyclopedia (care guide)High heat can also discolour it and damage the surface.GIA Gem Encyclopedia (care guide)Its natural colour already ranges from dull and grass greens to a bright sky blue.GIA Turquoise Description
Q4Can turquoise get wet, and how do you clean it?
Turquoise can be cleaned with warm soapy water, but it must never be steam-cleaned.GIA Gem Encyclopedia (care guide)Ultrasonic cleaners are to be avoided too, as the ultrasonic solution may discolour it.Gems & Gemology 1987 (Martin)Treatments with dye, oil, resin, wax or plastic are not permanent, so keep it away from all solvents, including dish-washing liquid.CIBJO Gemstone Book 2022Turquoise impregnated with oil or wax needs special care: avoid hot water and household chemicals.AGTA Gemstone Information Manual, 17th ed.Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.What this page can answer
Q5Does turquoise fade in the sun?
Turquoise is generally light-stable, but high heat can discolour it and damage the surface.GIA Gem Encyclopedia (care guide)Sunlight and artificial light on display are rated relatively safe.Gems & Gemology 1987 (Martin)
Q6Does turquoise scratch easily?
Yes, it scratches easily, so flush and pavé settings are best avoided, and prong, bezel and channel settings call for caution.Gems & Gemology 1987 (Martin)It is Mohs 5 to 6 with generally fair to good toughness.GIA Gem Encyclopedia (care guide)It also chips and cracks easily.CIBJO Gemstone Book 2022
Q7How does turquoise form, and what is the matrix?
Turquoise is a secondary mineral that forms near the surface as acidic, copper-bearing groundwater reacts with aluminium- and phosphorus-bearing minerals in the host rock.GIA Turquoise Description · G&G Winter 2023It occurs as veins and fracture fillings, sometimes as nodules, in host rocks such as iron-rich limonite or sandstone.GIA Turquoise Description · G&G Winter 2023The matrix is what remains of that host rock: limonite leaves dark brown markings and sandstone tan ones.GIA Turquoise Description · G&G Winter 2023
Q8What does "Persian blue" mean?
It is a colour name, not an origin: the trade calls top-colour sky-blue turquoise Persian blue whether or not it was mined in Iran, after the traditional source of that colour in Iran's Nishapur district.GIA Turquoise Description
Q9What does turquoise symbolize, and does it have healing powers?
There is no scientific evidence that turquoise 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)Jewelers of America and Japan's JJA list turquoise as the December birthstone.Cultural recordsThe V&A holds a gold ring from Lazio, Italy (1800–1860) set with fifteen turquoises, and its catalogue entry records that the stone's blue was thought to keep the evil eye away.Cultural records
Q10What makes high-quality turquoise?
Turquoise is judged on colour, texture and whether matrix is present; the most valuable material is an even medium blue with no matrix that takes a good polish.GIA Turquoise Quality FactorsLow-porosity, fine-textured material takes a waxy lustre when polished and is more valuable, while coarse, porous stones are usually treated to improve their appearance.GIA Turquoise Description
Sources cited in these answers ASA/CAP guidance (UK)
What this page can answer
This page covers
- How Turquoise 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 TurquoiseIdentification points from the research literature; how far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Turquoise4 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing TurquoiseCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of TurquoiseEach value with its source and check date
- Turquoise 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 TurquoiseHow people have used it, with museum objects
- Listing and disclosing TurquoiseThe listing name to use; what must be disclosed before sale
- Standard clauses that define TurquoiseWhich 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
- Turquoise
- Matrix markings (host-rock remnants)
- Host rock
If you reuse this animation, please credit LumaLark Wiki and link to this pageLicense: CC BY 4.0
Scene-by-scene transcript (8 scenes, with evidence grades and sources)
The caption of each scene in the animation above, with its evidence grade and sources.
Scene 1What turquoise is
Turquoise is a hydrated copper-aluminium phosphate and a secondary mineral
Scope: Covers the natural origin of turquoise as a supergene secondary copper aluminium phosphate mineral
Scene 2Setting: near-surface ground in dry, barren regions
Near-surface settings in dry, barren regions, where acidic copper-bearing groundwater seeps down and reacts with phosphorus- and aluminium-bearing minerals in the host rock; one such setting is the oxidized zone of copper-sulfide mineralized rock.
Scene 3One pathway · Step one: hydrothermal copper sulfides
In the first stage, hotter hydrothermal fluids lay down copper sulfide ore minerals such as bornite or chalcopyrite, creating mineralized rock.
Scene 4Step two: meteoric water percolates; the sulfides oxidize
Meteoric water percolates through the rock and dissolved oxygen oxidizes the sulfides to soluble copper sulfates, producing an acidic, copper-bearing solution.
Scene 5Step three: reaction with aluminium- (and phosphorus-) bearing minerals in the host rock
formed as acidic copper-bearing groundwater reacts with aluminium- (and phosphorus-) bearing minerals in the host rock
Scope: Applies to the natural supergene origin of turquoise
Evidence grade AScene 6Closer in on one fracture: the turquoise filling it
precipitating turquoise in veins, seams, or fractures, sometimes as nodular masses.
Scene 7Up close: microscopic crystal packing
Turquoise is an aggregate of microscopic crystals
Turquoise texture and porosity depend on microscopic crystal packing: low-porosity, fine-textured material takes a waxy luster when polished and is more valuable, while coarse, porous stones are usually treated to improve their appearance.
Evidence grade AScene 8What you end up seeing: matrix and colour
The mineral is normally embedded in its host rock, remnants of which give rise to dark brown (limonite) or tan (sandstone) matrix markings.
Turquoise color ranges from dull and grass greens to a bright sky blue; the traditional source of the top color is the Nishapur district of Iran, the country formerly known as Persia, and the trade calls this color Persian blue whether or not the stone was mined in Iran, so it is a color name, not an origin determination.
Evidence grade ATimescale: The source gives no absolute geological timescale for turquoise formation
In brief: Turquoise is a hydrated copper-aluminium phosphate and a secondary mineral; one formation route described by the sources takes place where copper-sulfide mineralized rock is oxidized (supergene).
Full research record (formation summary, where it forms, 3 formation steps, link to appearance, timescale, 2 supporting findings)
Turquoise is a hydrated copper-aluminium phosphate and a secondary mineral; one formation route described by the sources takes place where copper-sulfide mineralized rock is oxidized (supergene). Turquoise can form in more than one way. In one pathway, higher-temperature hydrothermal solutions first deposit copper sulfide ore minerals, chalcopyrite and bornite among them; afterwards, meteoric water percolating downward together with dissolved oxygen oxidizes those sulfides into soluble copper sulfates, and the acidic copper-bearing liquid then attacks aluminium-bearing minerals (along with phosphorus and potassium) in the surrounding rock, laying down turquoise that fills veins, seams or fractures and occasionally builds nodular masses. In general terms, turquoise is found only in a few dry, barren regions, where descending acidic, copper-rich groundwater meets phosphorus- and aluminium-bearing minerals; the source calls this a sedimentary process. The mineral is normally embedded in its host rock, remnants of which give rise to dark brown (limonite) or tan (sandstone) matrix markings.
Scope: Covers the natural origin of turquoise as a supergene secondary copper aluminium phosphate mineral; for filled, dyed or otherwise treated material, only its natural origin is addressed, not the treatment processes.
Sources GIA Turquoise Description · G&G Winter 2023
Where it forms
Host rocks such as iron-rich limonite or sandstone, as veins and fracture fillings, sometimes as nodular masses
Sources GIA Turquoise Description · G&G Winter 2023
How it forms, step by step
In the first stage, hotter hydrothermal fluids lay down copper sulfide ore minerals such as bornite or chalcopyrite, creating mineralized rock.
Sources GIA Turquoise Description · G&G Winter 2023
Meteoric water percolates through the rock and dissolved oxygen oxidizes the sulfides to soluble copper sulfates, producing an acidic, copper-bearing solution.
Sources GIA Turquoise Description · G&G Winter 2023
The acidic copper solution reacts with aluminium-bearing (as well as phosphorus and potassium) minerals in the host rock, precipitating turquoise in veins, seams, or fractures, sometimes as nodular masses.
Sources GIA Turquoise Description · G&G Winter 2023
Link to appearance
Turquoise is an aggregate of microscopic crystals: closely packed crystals give low porosity, fine texture, and a waxy luster when polished, whereas higher porosity gives coarse texture and dull luster; host-rock remnants produce dark brown (limonite) or tan (sandstone) matrix markings, and color ranges from dull to grass green to a bright, medium-toned sky blue.
Sources GIA Turquoise Description · G&G Winter 2023
Timescale
The source gives no absolute geological timescale for turquoise formation; it only notes that it was mined in Egypt more than 2000 years ago.
Sources GIA Turquoise Description · G&G Winter 2023
Supporting findings
Turquoise is a secondary (supergene) mineral, formed as acidic copper-bearing groundwater reacts with aluminium- (and phosphorus-) bearing minerals in the host rock; one route described by the sources takes place where copper-sulfide mineralized rock is oxidized.
Evidence grade AScope: Applies to the natural supergene origin of turquoise; excludes filling and other treatments.
Sources GIA Turquoise Description · G&G Winter 2023
One formation pathway is that hydrothermal copper sulfides are deposited first, then oxidized by meteoric water and dissolved oxygen to copper sulfates, which react with aluminium/potassium minerals in the host rock and deposit turquoise in fractures.
Evidence grade AScope: Describes one pathway starting from copper sulfides; the source states that turquoise can form in more than one way.
Sources G&G Winter 2023
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Zhushan County, Hubei, ChinaGIA calls China today’s largest producer, with most gem material from Hubei; G&G calls Zhushan County China’s most commercially significant locality
Sources GIA Birthstones · G&G Spring 2024 · Handbook of Mineralogy
- Nishapur, Razavi Khorasan, Iranmined for over 1,000 years; the traditional source of “robin’s egg blue”
Sources GIA Birthstones · Handbook of Mineralogy
- Tianhu East deposit, Hami, Xinjiang, Chinamined in antiquity; renewed mining around 2015 briefly supplied the Chinese market
Sources G&G Spring 2024
North America
- Arizona, United States
Sources GIA Birthstones
- Nevada, United States
Sources GIA Birthstones
- New Mexico, United States
Sources GIA Birthstones
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
Turquoise color ranges from dull and grass greens to a bright sky blue; the traditional source of the top color is the Nishapur district of Iran, the country formerly known as Persia, and the trade calls this color Persian blue whether or not the stone was mined in Iran, so it is a color name, not an origin determination.
Evidence grade AScope: Color names are trade/empirical terms; the source gives no detailed color mechanism.
Sources GIA Turquoise Description
Human use and museum objects
Museum evidence places one of the earliest datable uses of the mineral turquoise as beadwork in the Bactria-Margiana Archaeological Complex of about the late 3rd-early 2nd millennium BCE (Met 1983.535.2), recurring in Central America (Cleveland 1951.157, 1945.123) and Peru (1951.174); some "turquoise"-coloured objects in the collections are in fact glazed faience or glass, not the mineral.
Evidence grade AScope: Limited to objects whose collection material field records turquoise; turquoise-glazed faience, turquoise-coloured glass and similar imitations are excluded.
Sources The Met 1983.535.2 · Cleveland Museum of Art 1951.157 · Cleveland Museum of Art 1945.123 +3
- The Metropolitan Museum of Art — Necklace (1983.535.2)
- Cleveland Museum of Art — Beads Strung as a Necklace (1951.157)
- Cleveland Museum of Art — Necklace (1945.123)
- Cleveland Museum of Art — Necklace (1951.174)
- The Metropolitan Museum of Art — Necklace of Coral and Turquoise Beads (1979.206.568)
- The Metropolitan Museum of Art — Necklace (2008.190.218)
The Met holds a Bactria-Margiana Archaeological Complex (BMAC) turquoise necklace of about the late 3rd-early 2nd millennium BCE (acc. 1983.535.2, turquoise and white stone), among the earliest objects in the collection certainly of the mineral turquoise. In the Americas, the Cleveland Museum of Art holds a gold-and-turquoise bead necklace from Central Panama (Conte style, ca. 400-500 CE; acc. 1951.157), a Mixtec (Oaxaca, Mexico) necklace of gold, shell and turquoise of ca. 1200-1519 (acc. 1945.123) and a pre-1532 Peruvian necklace of turquoise and bone beads (acc. 1951.174). More recent North American and Tibetan pieces include a Zuni coral-and-turquoise necklace (Met 1979.206.568, early 20th century) and a Tibetan turquoise necklace (Met 2008.190.218, probably 19th century). Note that some "turquoise"-coloured objects in the collections are in fact turquoise-glazed faience or glass, not the mineral, and are excluded here.
Sources The Met 1983.535.2 · Cleveland Museum of Art 1951.157 · Cleveland Museum of Art 1945.123 +3
- The Metropolitan Museum of Art — Necklace (1983.535.2)
- Cleveland Museum of Art — Beads Strung as a Necklace (1951.157)
- Cleveland Museum of Art — Necklace (1945.123)
- Cleveland Museum of Art — Necklace (1951.174)
- The Metropolitan Museum of Art — Necklace of Coral and Turquoise Beads (1979.206.568)
- The Metropolitan Museum of Art — Necklace (2008.190.218)
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. Cultural attributions follow the holding institution's records and are not extrapolated.
Objects cited
- The Met 1983.535.2Turquoise, white stone
- Cleveland Museum of Art 1951.157gold and turquoise
- Cleveland Museum of Art 1945.123gold, shell, turquoise
- Cleveland Museum of Art 1951.174turquoise beads and bone
- The Met 1979.206.568Coral, turquoise, string
- The Met 2008.190.218turquoise, cotton, metal
Cultural records for this material: Birthstone list, Evil eye.
How it is identified
Turquoise is often imitated with common, inexpensive minerals such as howlite or magnesite that have been dyed, and infrared (FTIR) spectra clearly separate turquoise from these imitations.
Evidence grade AScope: Describes a laboratory method; it needs instruments and is not a way for readers to test stones themselves.
Sources G&G Winter 2024
Plastic and ceramic imitations of turquoise also exist; Gilson introduced an imitation turquoise in the early 1970s.
Evidence grade BScope: Names imitation types only; it gives no features for telling them apart.
Sources GIA Introduction to Imitation Gems
Other research findings
Turquoise texture and porosity depend on microscopic crystal packing: low-porosity, fine-textured material takes a waxy luster when polished and is more valuable, while coarse, porous stones are usually treated to improve their appearance.
Evidence grade AScope: Concerns the structure-appearance/value relationship; treatment details are outside this source.
Sources GIA Turquoise Description
The sources emphasize different reactants in turquoise formation: one names phosphorus- and aluminium-bearing minerals, the other aluminium- and potassium-bearing minerals; neither gives a single precise reaction equation.
Evidence grade CScope: The two wordings do not conflict: the ideal end-member formula of turquoise, CuAl6(PO4)4(OH)8·4H2O, contains no potassium, so potassium is not an essential major component (natural samples may carry traces); the potassium-bearing minerals can be read as the source of aluminium — the Tianhu East study in Xinjiang holds that at that deposit alumina was released from muscovite or sericite during weathering and phosphorus came mainly from diagenetic apatite in black shale (a supergene-origin hypothesis for that one deposit, not a general rule). No specific reaction equation or stoichiometry is given in the sources.
Sources GIA Turquoise Description · G&G Winter 2023 · Handbook of Mineralogy +1
To make it more stable, lower-quality turquoise is bonded together at the granular level with polymer resins; FTIR spectra reveal these resins even when they are hard to see under a microscope.
Evidence grade AScope: Describes the treatment and how laboratories detect it; it gives no market frequency.
Sources G&G Winter 2024
A Gems & Gemology note states that turquoise is usually impregnated with acrylic polymer or epoxy resin for stabilization.
Evidence grade AScope: The note's general remark, made while reporting one dyed and impregnated specimen; it is not a measured market frequency.
Sources G&G Fall 2015
Turquoise is judged on three basic quality factors: colour, texture, and whether matrix is present; the most valuable material is an even medium blue with no matrix that takes a good polish, while spiderweb turquoise has fine seams of matrix forming web-like patterns.
Evidence grade BScope: Quality factors as described by one educational source; not a grading standard and not a statement about the value of any piece.
Sources GIA Turquoise Quality Factors
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The authoritative sources emphasize different reactants in the formation mechanism (P+Al vs Al+K), and give no specific, balanced reaction equation.
- The sources provide no absolute geological timescale for turquoise formation.
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
- Turquoise
GB/T 16552—2017 Table A.2 “Turquoise” · CIBJO Gemmological Laboratories Book 2024 §7.2.1.249 “Turquoise”
Construction or treatment status
Natural; treatment common (require certificate to distinguish)
Treatments recorded for this material: Dyed, Waxed, Impregnated, 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
Turquoise is often subjected to dyeing, waxing and impregnation.
Under GB/T 16552-2017, dyeing counts as a treatment and must be stated in the name (§5.4.2.2 a); waxing (not listed separately in GB/T; Table 1 groups it with colourless oil or wax filling) counts as an optimization, so the plain gem name may be used (§5.4.2.1 a); impregnation is graded by the material used, and must be stated in the name wherever it counts as a treatment (§5.4.1, Table 1), while impregnation that is the Table B.1 “density optimization” counts as an optimization that must be noted on the quality document (§5.4.2.1 b). Do not assume it is unenhanced.
What this means for you
Before buying, check the recommended listing name "Turquoise" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- See “Disclosure and cautions” above
- Disclosure rules for the treatments above can change as authorities update their standards; re-check before relying on this page.
- 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
Turquoise — care (cleaning): Warm soapy water is safe, but it must never be steam-cleaned.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Turquoise Care and Cleaning Guide: Section “Cleaning” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (cleaning): ultrasonic and steamer: avoid; note: avoid heat and chemicals; ultrasonic solution may discolour it.
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, Turquoise row, CLEANING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (heat): generally light-stable, but high heat can discolour it and damage the surface.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Turquoise Care and Cleaning Guide: Section “Stability” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
care (chemicals)2 sources compared
Turquoise — care (chemicals): It dissolves slowly in hydrochloric acid, and chemicals, cosmetics and even skin oils or sweat can discolour it.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Turquoise Care and Cleaning Guide: Section “Stability” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (chemicals): Some stones are treated to improve their surface appearance, and heat or solvents can damage that treated surface.
GIA Gem Encyclopedia (care guide)
- Treatment state
- treated
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Turquoise Care and Cleaning Guide: Section “Cleaning” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — 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
- Only after these treatments
- dyeing, impregnation, surface waxing
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Turquoise, p.86; §6.2 k (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Turquoise — care (wear): Mohs 5 to 6 with generally fair to good toughness
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- GIA Gem Encyclopedia — Turquoise Care and Cleaning Guide: Section “Hardness and toughness” (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (special care): impregnated with colourless oil or wax to enhance or create colour: special care (SC); avoid hot water and household chemicals.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- surface waxing
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XVI, Gemstone Information Chart, Turquoise W, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (special care): dyed for colour: special care (SC), with extra caution; avoid hot water and household chemicals.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- dyeing
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XVI, Gemstone Information Chart, Turquoise D, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (special care): plastic-impregnated to create or improve colour and add durability: special care (SC); avoid hot water and household chemicals.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- treated
- Only after these treatments
- impregnation
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.XVI, Gemstone Information Chart, Turquoise I, CARE REQUIRED / SPECIAL ADVICE (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (setting): prong, bezel and channel: use caution; flush and pavé: avoid; note: scratches 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, Turquoise row, SETTING column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (repair): jeweller's torch, pickle pot, polishing and thermal shock: avoid; note: avoid heat and chemicals; heat lowers its value and polishing compound discolours it.
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, Turquoise row, REPAIR column (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — care (display): heat in the display case, sunlight and artificial light: relatively safe; note: it is porous, so skin oils, lotions and the like may discolour it during handling.
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, Turquoise 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
CleaningCleaning Turquoise: the GIA Gem Encyclopedia (Gemological Institute of America) states that, in any treatment state, it can be cleaned with warm soapy water but never with steam; Martin's Gemstone Durability: Design to Display states that untreated material should not be cleaned ultrasonically or with steam, as ultrasonic cleaning fluid may discolour Turquoise. Chemicals: GIA states that, in any treatment state, Turquoise slowly dissolves in hydrochloric acid, and chemicals, cosmetics, skin oils and sweat can all discolour it; for material treated to improve its surface appearance, heat or solvents will damage the treated surface. CIBJO states, for dyeing, impregnation and surface waxing only, that dyeing, oiling, resin, wax or plastic impregnation are not permanent, so keep it away from all solvents (including detergents of every kind), chemicals and heat. Heat: GIA states that, in any treatment state, it is generally stable to light, but high heat can discolour Turquoise and damage the surface. Wear: GIA states that, in any treatment state, Mohs hardness is 5–6 and toughness fair to good; Martin states that untreated material scratches easily, prong, bezel and channel settings need care, and tension and pavé settings should be avoided.
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.
any treatment state
- Warm soapy water is safe, but it must never be steam-cleaned
- generally light-stable, but high heat can discolour it and damage the surface
- It dissolves slowly in hydrochloric acid, and chemicals, cosmetics and even skin oils or sweat can discolour it
- Mohs 5 to 6 with generally fair to good toughness
untreated
- ultrasonic and steamer: avoid; note: avoid heat and chemicals; ultrasonic solution may discolour it
- prong, bezel and channel: use caution; flush and pavé: avoid; note: scratches easily
- jeweller's torch, pickle pot, polishing and thermal shock: avoid; note: avoid heat and chemicals; heat lowers its value and polishing compound discolours it
- heat in the display case, sunlight and artificial light: relatively safe; note: it is porous, so skin oils, lotions and the like may discolour it during handling
treated
treated (Only after these treatments: dyeing, impregnation, surface waxing)
treated (Only after these treatments: surface waxing)
treated (Only after these treatments: dyeing)
treated (Only after these treatments: impregnation)
Durability and wearing
Toughness
Fair to Good
Sources GIA Gem Encyclopedia (care guide)
Treatments and identification leads
Registered treatmentsThe treatments registered for Turquoise are surface waxing, dyeing, impregnation and filling, all with status treated. Values not givenSurface waxing and dyeing have stability not stable, with prevalence common and rare respectively; impregnation has stability stable and prevalence occasional; for filling, stability and prevalence are not given by the cited source. Identification cluesThe identification leads for dyeing are uneven colour under magnification, mostly concentrated in fractures, gaps between grains or surface depressions, and a UV-visible spectrum different from natural samples; the leads for filling are a lustre at filled areas that differs from the host, gas bubbles, wax possibly sweating out on contact with a thermal needle when the filler is wax, characteristic bands of the filler detectable in the infrared spectrum, and luminescence imaging equipment showing the filler's distribution. Values not givenIdentification leads for surface waxing and impregnation are not given by the cited source. A value not given by the cited source is not the same as "none".
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| surface waxingStatus: treated | commonly | unstable | — | waxing | — |
| dyeingStatus: treated | rarely | unstable | Treatment | — | See identification leads |
| impregnationWhich form of it: impregnation with plasticStatus: treated | commonly | unstable | — | — | — |
| impregnationWhich form of it: Zachery treatment (coloured, impregnated with a potassium compound)Status: treated | occasionally | stable | — | — | — |
| fillingStatus: treated | — | — | Graded — see §5.4.1, Table 1 | — | See identification leads |
| Density optimization | — | — | Optimization (annotation required) | — | — |
| impregnation with a colourless agent | — | — | — | impregnation with a colourless agent | — |
| impregnation with a coloured agent | — | — | — | impregnation with a coloured agent | — |
| chemical treatment | — | — | — | chemical treatment | — |
Where each treatment acts (schematics): Waxed · Dyed · Impregnated · Filled / Fracture-filled
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022 · GB/T 16553—2017; GB/T 16552—2017 Table B.1; 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 Turquoise, the name register records "Spider's Web Turquoise" and "Turquoise Matrix", for which no restriction on use as a name is recorded (CIBJO Gemstone Book 2022 Annex 8 “Spider’s Web Turquoise”; CIBJO Gemstone Book 2022 Annex 8 “Turquoise Matrix”); 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).
Standard and listing namesThe Chinese formal name for Turquoise is given in GB/T 16552—2017 Table A.2; a shortened Chinese name is in common market use, and in the trade that short name also often refers to dyed magnesite, so the actual material must be checked piece by piece; the suggested listing name is Turquoise. Names in four languagesThe four-language names are given in Simplified Chinese, Traditional Chinese, English (Turquoise) and Japanese (a transliteration and a kanji name), and the Japanese GSJ formal name is written as the kanji name with turquoise; the mineralogical name is Turquoise, a hydrated copper aluminium phosphate. National standard namesGermany (RAL) writes Türkis, and the EU and France (DGCCRF) write Turquoise. Institution usageAmong authority wordings, the CIBJO Gemmological Laboratories Book 2024 lists Turquoise; the FTC source text has no wording for this name (checked); GIA and Gem-A have not been checked; bodies without a recorded wording show Turquoise's own English name, which does not represent their position. Sub-names and unacceptable namesSpider's Web Turquoise and Turquoise Matrix are subordinate names (varieties or subtypes) registered from the CIBJO Gemstone Book 2022.
Name register
Every name recorded for this entry, with how it is classified, whether it may be matched to this entry automatically, whether it may be used as a product name, and the clause it rests on.
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| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (3) | ||||
| Spider's Web TurquoiseEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Spider’s Web Turquoise” |
| Turquoise MatrixEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Turquoise Matrix” |
| 松石Simplified Chinese | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited); Note: A match by name, not by specimen: in the trade the same name is also used for dyed magnesite, so each material has to be checked individually and this row does not extend to it. |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- トルコ石／ turquoise
- Chinese formal name
- 绿松石 (GB/T 16552—2017 Table A.2)
- Mineralogical name
- Turquoise (hydrated Cu-Al phosphate)
- Trade names and synonyms
- Turquoise Matrix (narrower name (variety or subtype)) · Spider's Web Turquoise (narrower name (variety or subtype))
Four-language names
- 简体中文
- 绿松石
- 繁體中文
- 綠松石
- English
- Turquoise
- 日本語
- ターコイズ／トルコ石
National and regional formal names
- Germany (RAL)
- Türkis
- European Union
- Turquoise
- France (DGCCRF)
- Turquoise
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Phosphate minerals
- Identity tier
- Mineral species
- Mineral chemical class
- Phosphates
- Construction or treatment status
- Natural; treatment common (require certificate to distinguish)
Treatments listed by standards
GB/T Table B.1The Turquoise row of GB/T 16552—2017 Annex B, Table B.1 lists: filling, which improves or changes durability and appearance and is classed by the GB/T 16552—2017 grades; density optimization, which improves durability and appearance and is classed as optimization with an annotation required; and dyeing, which improves or changes colour and is classed as treatment. The notes to Table B.1 and the definitions of the filling grades are on the Gem treatments page. JJA/AGL designationsThe JJA/AGL (Japan) 2025 table gives the species of Turquoise as turquoise, lists an untreated tier separately, and also lists waxing (waxed), impregnation with a colourless agent and with a coloured agent (impregnated), and chemical treatment; how to read the JJA/AGL table is explained on the Gem treatments page.
GB/T 16552-2017, Annex B, Table B.1
Table B.1, row “Turquoise” (p.16):
This table scrolls sideways on narrow screens.
| Method | Effect | Category |
|---|---|---|
| Filling | Improves or changes durability and appearance | Graded — see §5.4.1, Table 1 |
| Density optimization | Improves durability and appearance | Optimization (annotation required) |
| Dyeing | Improves or changes colour | Treatment |
What Table B.1 is, and how the “see 5.4.1” grades are defined: see the GB/T 16552: optimization vs treatment page.
JJA/AGL (Japan) table of principal gem names, 2025
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| Gem name | Species | Colour | Listed in the table | Notes |
|---|---|---|---|---|
| Turquoise | Turquoise | blue, greenish blue, bluish green, green | an untreated tier is listed; waxing (Waxed); impregnation with a colourless agent (Impregnated); impregnation with a coloured agent (Impregnated); chemical treatment (no matching treatment page on this site) |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.14
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
The chemical composition of Turquoise is registered from GB/T 16553—2017 as CuAl6(PO4)4(OH)8·5H2O, with IMA nomenclature status A (approved by the IMA); structurally it is almost always a cryptocrystalline aggregate, mostly occurring as massive, platy, nodular or crust-like material. Mohs hardness is registered as 5–6 by the Handbook of Mineralogy and 3–6 by GB/T 16553—2017; no cleavage. Density 2.4–2.9 g/cm³; per the site note, the cited clause gives 2.76 with a stated tolerance of +0.14, −0.36, and the range is worked out from that. Refractive index 1.61–1.65; per the site note, the cited clause also gives finer sub-ranges, and the overall value is used. Optic character is an anisotropic aggregate, birefringence not measurable on an aggregate; transparency translucent to opaque. Untreated: pleochroism not measurable on an aggregate; lustre waxy to vitreous, sometimes earthy; long-wave UV fluorescence none to weak, greenish yellow, bluish green or blue; short-wave UV fluorescence none. The UV-visible spectrum shows a 422nm absorption band and a 430nm absorption band.
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
Turquoise — nomenclature status: IMA status A: approved (accepted by the IMA after it was set up in 1958).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Turquoise — composition (chemistry): CuAl₆ (PO₄) ₄ (OH) ₈·5H₂O
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — composition (phase): turquoise
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Turquoise — structure (overall): almost always a cryptocrystalline aggregate, usually massive, platy, nodular or crust-like.
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Mohs hardness2 sources compared
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))
Turquoise — Mohs hardness: 5–6
Handbook of Mineralogy
Source & check 2026-09-20
- Source
- Handbook of Mineralogy — Turquoise (Mineral Data Publishing): p. 1, Physical Properties (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Turquoise — Mohs hardness: 3–6
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.13 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Turquoise — 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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — stability: chips and cracks easily; porous, so keep it away from coloured liquids; no ultrasonic cleaning.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code b, special-care code c, special-care code j
- Treatment state
- untreated
Source & check 2026-09-21
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Turquoise, p.86; §6.2 b, c, j (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
For Turquoise, the stability of surface waxing is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- surface waxing
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Turquoise, the stability of dyeing is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- dyeing
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Turquoise, the stability of impregnation with plastic is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
- Which form of it
- impregnation with plastic
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Turquoise, the stability of Zachery treatment (coloured, impregnated with a potassium compound) is “stable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
- Which form of it
- Zachery treatment (coloured, impregnated with a potassium compound)
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
Physical properties
Turquoise — density: 2.4–2.9 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 2.76, with a stated tolerance of +0.14 / -0.36. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Turquoise — optic character: anisotropic aggregate
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — refractive index: 1.61–1.65
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — birefringence: not measurable on an aggregate
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — transparency: translucent to opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Turquoise — pleochroism: not measurable on an aggregate
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — fluorescence (long-wave UV): none to weak, green-yellow, blue-green, blue
GB/T 16553—2017
UV fluorescence (long-wave UV)green-yellowblue-greenbluenone–weakDots 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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — fluorescence (short-wave UV): 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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — spectrum (UV-visible): 422 nm absorption band; 430 nm 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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — spectrum (infrared): In the mid-infrared fingerprint region, phosphate ion vibration gives rise to characteristic infrared absorption bands; OH vibration does the same in the functional group region.
The added bands depend on the filler: turquoise filled with acrylic resin shows an extra group at about 1 731 cm⁻¹, 2 850 cm⁻¹ and about 2 923 cm⁻¹, while turquoise filled with epoxy resin shows an extra group at 1 510 cm⁻¹, 1 609 cm⁻¹, 2 872 cm⁻¹ and 2 930 cm⁻¹.
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): §5.2.13 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Turquoise — magnification: cryptocrystalline structure, granular structure, compact massive structure, generally dark, white or yellowish-brown impurities forming network veins or spots.
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): §5.2.13 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
body colour2 sources compared
Turquoise — body colour: Light to medium blue, greenish blue to green, often mottled.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Aquamarine, Chrysocolla, Dioptase and other entries also name blue or a bluish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Turquoise — body colour: light to medium blue, greenish blue to green, commonly with black, yellowish brown or white net-like veining or impurities.
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 Nephrite, Dushan Yu / Dushan Jade, Vesuvianite / Idocrase and other variety clauses also name blue or a bluish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.13 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
How the sources relate
- CIBJO Gemmological Laboratories Book 2024 and GB/T 16553—2017
The two entries agree: light to medium blue, greenish blue to green. GB/T 16553—2017 adds that black, yellowish brown or white net-like veining or impurities are common; the CIBJO Gemmological Laboratories Book notes that the material is often mottled.
Quality factors
Turquoise — quality factor (lustre): waxy to vitreous, sometimes earthy
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): §5.2.13 (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): 1.63 / 2.65; Closest values: 1Freshwater Natural Pearl 1.605 / 2.72, 2Sugilite 1.61 / 2.77, 3Akoya Cultured Pearl 1.605 / 2.75, 4Larimar 1.62 / 2.82, 5Giant Clam Shell 1.605 / 2.79
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
Dyeing and filling of Turquoise can be identified. GB/T 16553—2017 can only be used as a reference for the Turquoise entry and does not govern it directly: in dyed Turquoise, uneven colour can be seen under magnification, mostly concentrated in fractures, gaps between grains or surface hollows, and the UV-visible spectrum differs from that of natural samples. In filled Turquoise, the filled areas differ in lustre from the host under magnification and contain gas bubbles; if the filler is wax, wax may exude when touched with a hot needle; infrared spectroscopy can detect the characteristic bands of the filler, and luminescence imaging equipment such as a UV fluorescence viewer can show how the filler is distributed. The CIBJO laboratory protocol requires impregnation, dyeing, assembled stones, imitation matrix and synthetics to be checked in particular, with a note that EDXRF compositional analysis is used for the Zachery treatment. No synthetic counterpart of Turquoise is on the market. Among Turquoise on the market, surface waxing is common, dyeing rare, plastic impregnation common, and the Zachery treatment (colour enhancement with impregnation by potassium-bearing compounds) occasional. The required tests and methods of the CIBJO laboratory protocol are 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: §6.1.88.
How far testing can go
Turquoise that has undergone dyeing can be identified by the following features: Under magnification the colour is unevenly distributed and mostly concentrated in fissures, between grains or in surface hollows; its UV-visible spectrum is not the same as that of natural material.
GB/T 16553—2017
- Treatment state
- colour treated
- Does this standard apply
- can be followed as a reference only
- Treatment
- dyeing
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.13 (dyeing) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise that has undergone filling can be identified by the following features: Under magnification the surface luster of the filled part differs from that of the host jade and gas bubbles are visible in the filled area; if the filler is wax, touching it with a hot needle may make wax seep out; 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): §5.2.13 (filling) (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Turquoise — 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 Turquoise in trade, the reported frequency of surface waxing is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- surface waxing
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Turquoise in trade, the reported frequency of dyeing is “rarely”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- dyeing
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
For Turquoise in trade, the reported frequency of impregnation with plastic is “commonly”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
- Which form of it
- impregnation with plastic
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
For Turquoise in trade, the reported frequency of Zachery treatment (coloured, impregnated with a potassium compound) is “occasionally”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
- Which form of it
- Zachery treatment (coloured, impregnated with a potassium compound)
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
Turquoise — what the CIBJO laboratory protocol says to watch for: impregnation, dye, composites, imitation matrix, synthetics
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Turquoise — notes on test methods in the CIBJO laboratory protocol:
| Test method | What the protocol notes for it |
|---|---|
| EDXRF chemistry: | Zachery treatment |
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
Turquoise is defined directly in the CIBJO Gemmological Laboratories Book 2024 under the entry name Turquoise, described as translucent to opaque and frequently mottled, in light to medium blue and greenish blue through to green; the cross-check result is that it is defined directly by CIBJO and also appears in the GB/T annex. Turquoise also has an IMA Mineral List entry, likewise listed as Turquoise, which gives the chemical formula CuAl6(PO4)4(OH)8(H2O)4 together with A 1967, cross-checked against the RRUFF/IMA master mineral list; the data are in the public domain.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Turquoise | 7.2.1.249 | Light to medium blue, greenish blue to green, often mottled, translucent to opaque; may show dark splotches or veins of matrix | Defined directly by CIBJO; also present in the GB/T annex. |
| Turquoise | IMA Mineral List entry | Turquoise CuAl6(PO4)4(OH)8(H2O)4 A 1967 | Cross-checked against the RRUFF/IMA master mineral list (public domain data). |
Evidence and sources
Authority basis and clause sources
Sources
Further reading
Recorded cultural contexts
The U.S. Jewelers of America roster lists Turquoise for December; and Japan's JJA 2021 revised roster lists Turquoise for December. This records trade-association convention only; it does not establish material identity, natural origin, treatment, provenance, or effect.
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| 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, December row: Turquoise |
| 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, December row: Turquoise |
The V&A holds a gold ring from Lazio, Italy (1800–1860) set with fifteen turquoises; its catalogue entry records that the stone's blue colour was thought to keep the evil eye away.
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| Publisher or holder | Region | From / period | Source and locator |
|---|---|---|---|
| Victoria and Albert Museum | Italy | 19th century | Victoria and Albert Museum, London — museum no. 440-1868: turquoise-set gold ring, Lazio (Italy), 1800–1860 museum no. 440-1868, catalogue entry |
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
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| Page | Content | Status |
|---|---|---|
| Browsing family | Phosphate minerals | Live |
| Treatments recorded for this material | Dyed, Waxed, Impregnated, Filled / Fracture-filled | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Turquoise 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.