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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral / gemstone variety · Natural identity; treatment status unknown
White Sapphire
Also known asColourless Sapphire
A colorless, transparent variety of gem corundum. "White" is the trade name's wording; the color it refers to is colorless. This page compares how the major standards and institutions name it, what must be disclosed when selling it, whether it can be worn every day, how it is treated and identified, and which source each conclusion comes from.
Price, rarity and origin are outside the scope of this wiki.
What this page can answer
This page covers
- How White Sapphire 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 White SapphireIdentification points from the research literature
- Caring for and wearing White SapphireCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of White SapphireEach value with its source and check date
- White Sapphire in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Which of GIA, FTC, CIBJO and Gem-A have a name for it on record, and do those agree?
- Listing and disclosing White SapphireThe listing name to use; what must be disclosed before sale
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
White sapphire is the colourless to near-white variety of gem corundum (Al2O3), and corundum is a classic allochromatic mineral: very pure corundum (formula Al2O3) is completely colourless, its colour arising from trace elements or other point defects incorporated into the lattice. White sapphire is therefore colourless/white because it lacks sufficient colouring elements — not because of blue sapphire's colour mechanism. Corundum has six major chromophores (Fe3+, Cr3+, V3+, Fe2+-Ti⁴⁺, h•-Fe³⁺ and h•-Cr³⁺) whose kinds and concentrations determine colour; the white variety lies at the low end of these chromophore contents. This record only explains why it is colourless and does not transfer the Fe2+-Ti⁴⁺ charge-transfer mechanism of blue sapphire to the white variety.
Scope: Applies to explaining the cause of colour (colourlessness) of colourless / white gem-quality corundum (white sapphire) and its status as 'the colourless end-member of an allochromatic mineral'; does not cover the Fe2+-Ti⁴⁺ colouration of blue sapphire, nor locality determination or treatment.
Sources G&G Spring 2020 · G&G Fall 2023
Where it forms
The same genetic settings as corundum (metamorphic rocks, alkali basalts, etc.), but with protoliths/crystals poor in colouring elements so the corundum stays colourless.
Sources G&G Spring 2020 · G&G Fall 2023
As a corundum gem variety, white sapphire occurs in the colourless to near-colourless fraction of corundum deposits.
Sources G&G Spring 2020 · G&G Fall 2023
How it forms, step by step
Alumina-rich protoliths form corundum (Al2O3) crystals under metamorphic or magmatic conditions.
Key point: the crystallising system lacks sufficient colouring elements (Cr, Fe, Ti, V, etc.), leaving a nearly pure lattice.
Nearly pure corundum carries no absorption colour and is colourless/white (the colourless end of an allochromatic mineral).
Eroded and transported crystals may concentrate in placers as colourless gem corundum.
Link to appearance
The colourless/white appearance comes from a lack of colouring elements, i.e. the colourless end of allochromatic corundum; adding a chromophore (e.g. Fe2+-Ti⁴⁺) turns it blue, so the blue mechanism must not be used to explain white.
Sources G&G Spring 2020 · G&G Fall 2023
Timescale
The cited sources give no timescale specific to white sapphire.
Sources G&G Spring 2020 · G&G Fall 2023
Related base materials
- Corundum (Al2O3): Mineral parent: white sapphire is the colourless/near-white variety of gem-quality corundum (the colourless end-member of an allochromatic mineral)
- Sapphire (gem corundum other than ruby): Also gem-quality corundum; the colours differ, so the colour must be stated separately, and colour-causing mechanisms may not be conflated
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Chimwadzulu Hill, MalawiOnly a fraction (5–30%) of run-of-mine stones
- MadagascarOnly a fraction (5–30%) of run-of-mine stones
Asia
- Sri Lanka
North America
- Rock Creek, Montana, United States
- Eldorado Bar, Montana, United StatesOnly a fraction (5–30%) of run-of-mine stones
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 the origin determination guide and the overview of recorded localities.
Causes of colour and optical effects
Very pure corundum (Al2O3) is completely colourless; white/colourless sapphire is colourless because it lacks sufficient chromophore elements, not through blue sapphire's colour mechanism.
Evidence grade AScope: The general rule for allochromatic minerals; the colourless cause does not involve blue sapphire's Fe2+-Ti⁴⁺ charge transfer.
How it is identified
Rubies and sapphires that look alike may be natural, synthetic or treated, and the unaided eye with routine methods cannot decide reliably — synthetic material may even lack diagnostic inclusions and growth features. Laboratory separation rests on measurable properties: trace-element chemistry such as energy-dispersive X-ray fluorescence (EDXRF) can flag synthetic stones by the presence of trace elements including Ni, Mo, La, W, Pt, Pb and Bi, while Ga/Mg/Fe/Ti fingerprints and inclusion scenes support origin calls; glass filling and coating (for example cobalt coating marked by facet-junction and surface speckling) must be detected under magnification and instrumentation. Limitations: origin determination relies on reference databases and involves overlap between sources, so it carries uncertainty; the final conclusion must be issued by an accredited gemological laboratory through testing.
Evidence grade AScope: Identification and separation points; origin determination is uncertain and must be issued by an accredited gemological laboratory, and no self-test thresholds are given.
Origin labels for white sapphire (Sri Lanka, Myanmar, or China, for instance) are often used to support a premium, yet origin cannot be inferred from appearance or name. Origin determination is a comparison against reference databases of known localities: a laboratory measures trace-element suites by LA-ICP-MS and weighs inclusion features such as rutile silk, clouds, and growth zoning against specimens of documented provenance. The judgement is relative - the characteristic ranges of different localities overlap, deposits with no reference material cannot be assigned, and a single deposit is internally variable; heating and other treatments alter the measurable features, so treatment status must be settled first, and an individual stone may therefore return an "inconclusive" result. An origin call must be issued by an accredited laboratory for a specific specimen, and "consistent with a locality" is not the same as "mined there".
Evidence grade AScope: Origin cannot be inferred from appearance or name; conclusions are probabilistic and must be issued by an accredited laboratory for a specific specimen; no self-test criteria are given here.
Other research findings
Corundum has six major chromophores (Fe3+, Cr3+, V3+, Fe2+-Ti⁴⁺, h•-Fe³⁺, h•-Cr³⁺) whose kinds and concentrations determine colour; the white variety is the low-chromophore end.
Evidence grade AScope: The overall chromophore framework for corundum; no element quantification for a given white specimen.
White sapphire is a colour variety of gem corundum (all gem corundum other than ruby is sapphire and must have its colour stated); it is not an independent mineral species, and its colourlessness is not due to blue sapphire's cause.
Evidence grade AScope: A naming/classification statement; it does not determine the origin or locality of a given specimen.
Overall, white sapphire is gem corundum lacking sufficient chromophores: pure Al2O3 is colourless, and only adding a chromophore (e.g. Fe2+-Ti⁴⁺) makes it blue, so white and blue have distinct causes that must not be conflated.
Evidence grade BScope: A multi-source summary; a given specimen's chromophore content and colour depth require measurement.
Limits of this research
- Research status: Only partial material-specific findings found; gaps are stated as gaps
- The cited sources explain the white/colourless variety via corundum's allochromatic colour chemistry and give no white-sapphire-specific locality or quantitative composition.
- The Fe2+-Ti⁴⁺ charge-transfer mechanism of blue sapphire must not be applied to the white variety; treated and synthetic white corundum are outside this formation layer.
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
- White Sapphire
IMA Mineral List 2026-07 “Corundum” · CIBJO Gemmological Laboratories Book 2024 §7.2.1.263 “White sapphire”
Construction or treatment status
Natural identity; treatment status unknown
Related:Disclosure and cautions
This page cannot answer
Natural? · Origin · Price
A lab report settles these; this wiki covers naming and disclosure.
Related:What this page can answer
Answer at a glance
White Sapphire's material identity has open questions that are not fully settled; this site lists it as "White Sapphire" pending further verification.
Evidence
- CIBJO · 7.2.1.263
What this means for you
Before buying, check the recommended listing name "White Sapphire" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- This entry's exact material identity is not fully settled.
- See “Disclosure and cautions” above
- Last reviewed
- 2026-09-26
Care and wear
Care
care (cleaning)2 sources compared
White Sapphire — care (cleaning): in its entry on colourless sapphire (natural or synthetic), the GIA 4Cs blog rates ultrasonic and steam cleaning as usually safe.
GIA 4Cs blog (2016)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- GIA 4Cs blog, “What Are Simulated Diamonds?” (2016-12-20): Section: main text (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
White Sapphire — care (cleaning): GIA says ultrasonic and steam cleaning is normally safe only for untreated, heated or lattice-diffused sapphire; filled or dyed stones should just be wiped with a damp cloth.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- GIA Gem Encyclopedia — Sapphire Care and Cleaning Guide: Section “Cleaning” (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
White Sapphire — care (chemicals): According to GIA, boric acid powder attacks the surface of corundum, untreated stones included.
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- GIA Gem Encyclopedia — Sapphire Care and Cleaning Guide: Section “Stability” (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
care (wear)2 sources compared
White Sapphire — care (wear): the GIA 4Cs blog notes colourless sapphire's hardness of 9 and excellent toughness, putting its durability somewhat close to diamond's.
GIA 4Cs blog (2014)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- GIA 4Cs blog, “Jewelry Buyer’s Guide to Diamond Alternatives” (2014-04-30): Section: main text (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
White Sapphire — care (wear): GIA describes corundum of every colour as a very durable jewellery gem
GIA Gem Encyclopedia (care guide)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- GIA Gem Encyclopedia — Sapphire Care and Cleaning Guide: Section “Hardness and toughness” (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Common care questions and matching entries
Each question links to the matching entries on this page; whether they answer it fully, go by the entry wording.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | in its entry on colourless sapphire (natural or synthetic), the GIA 4Cs blog rates ultrasonic and steam cleaning as usually safe; GIA says ultrasonic and steam cleaning is normally safe only for untreated, heated or lattice-diffused sapphire; filled or dyed stones should just be wiped with a damp cloth |
| Contact with acids, alkalis and household chemicals | According to GIA, boric acid powder attacks the surface of corundum, untreated stones included |
| Wearing limits (knocks, settings) | the GIA 4Cs blog notes colourless sapphire's hardness of 9 and excellent toughness, putting its durability somewhat close to diamond's; GIA describes corundum of every colour as a very durable jewellery gem |
Durability and wearing
Toughness
Excellent toughness; no cleavage
Cleavage
no cleavage
Sources GIA Gem Encyclopedia (care guide)
VerifyNames, standards, technical facts, clauses and sources
Names
Besides White Sapphire, the name register records "Colourless Sapphire", for which no restriction on use as a name is recorded.
Names in four languagesThe four-language names of White Sapphire are the Simplified and Traditional Chinese names, English White Sapphire and the Japanese name. Chinese standard nameIts GB/T naming counterpart is Sapphire (GB/T 16552—2017 Table A.1); the name itself is not listed in the standard and is formed by adding a colour qualifier to the base name Sapphire. Trade and mineralogical namesThe trade name or synonym is Colourless Sapphire, recorded as an English synonym with no restriction recorded on its use as a name. Mineralogically, it is described as a colourless, transparent gem variety of corundum. Recommended listing nameThe suggested listing name is White Sapphire. Institution usageFor authority wording, the CIBJO Gemmological Laboratories Book 2024 records White Sapphire, the FTC text on file has no wording for White Sapphire (checked), and GIA and Gem-A are unchecked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesThe entry carries its own Japanese name, and GSJ's wording for White Sapphire is not yet verified by this site.
Name register
Every name recorded for this entry, with how it is classified, whether it may be matched to this entry automatically, whether it may be used as a product name, and the clause it rests on.
This table scrolls sideways on narrow screens.
| Name | Type | Matching | Use as a name | Basis |
|---|---|---|---|---|
| no restriction recorded (1) | ||||
| Colourless SapphireEnglish | synonym | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- ホワイト・サファイア (not yet checked for this body — the entry's own Japanese name is shown)
- GB/T naming counterpart (this name is not in the standard)
- 蓝宝石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- White sapphire: colourless, transparent corundum gem variety
- Trade names and synonyms
- Colourless Sapphire (synonym)
Four-language names
- 简体中文
- 白色蓝宝石
- 繁體中文
- 白色藍寶石
- English
- White Sapphire
- 日本語
- ホワイト・サファイア
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Oxide minerals
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Oxides / hydroxides
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The composition (phase) of White Sapphire is corundum, transparency is transparent and the body colour is colourless (treatment status: untreated); this site notes that in Chapter 7 of the CIBJO Gemmological Laboratories Book the colour descriptions of entries such as colourless tourmaline, crystal opal and colourless beryl also include colourless. Mohs hardness 9, density 3.95–4.1 g/cm³, refractive index 1.757–1.779 and birefringence 0.008–0.01 are all taken from sapphire as a whole (regardless of colour and origin); for density the cited clause gives 4.00 with an allowed deviation of +0.10/−0.05, from which the limits are derived; for refractive index the cited clause gives 1.762–1.770 with an allowed deviation of +0.009/−0.005, from which the limits are derived. Chemical composition, fluorescence, UV-Vis spectrum, infrared spectrum, magnification and similar items are given in the cited clauses for sapphire as a whole category (regardless of colour and origin); they are not repeated among the material facts for white sapphire, see the sapphire entry.
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”.
Chemical composition, luminescence, UV-visible spectrum, infrared spectrum, magnification: these whole-class features are given in the cited clause for sapphire as a whole (all colours and origins), so they are not repeated on the White Sapphire page; see the material facts on the Sapphire entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of White Sapphire (how to read class-level values).
Definition
White Sapphire — composition (phase): corundum
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Durability
White Sapphire — Mohs hardness: 9
GB/T 16553—2017
Reference points on this site: Talc 1–3, Fluorite 4, Apatite 5–5.5, Orthoclase 6–6.5, Topaz 8, Diamond 10 (Source: GB/T 16553—2017); Gypsum 1.5–2, Calcite 3, Quartz 7 (Source: Handbook of Mineralogy); Corundum 9 (Source: GIA Gem Encyclopedia (care guide))
- Does this standard apply
- applies to this entry
- What this covers
- sapphire as a whole (all colours and origins)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
White Sapphire — density: 3.95–4.1 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- sapphire as a whole (all colours and origins)
- Qualification
The clause we cite gives 4.00, with a stated tolerance of +0.10 / -0.05. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
White Sapphire — refractive index: 1.757–1.779
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- sapphire as a whole (all colours and origins)
- Qualification
The clause we cite gives 1.762–1.770, with a stated tolerance of +0.009 / -0.005. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
White Sapphire — birefringence: 0.008–0.01
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- sapphire as a whole (all colours and origins)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.3 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
White Sapphire — transparency: transparent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
White Sapphire — body colour: Colourless.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Achroite, Crystal Opal, Goshenite and other entries also name colourless.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- Fact checked on
- 2026-09-26
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
This material (RI / SG midpoints): 1.768 / 4.03; Closest values: 1Rhodolite 1.755 / 3.9, 2Almandine 1.79 / 3.9, 3Grossular 1.745 / 3.9, 4Tsavorite 1.74 / 3.9, 5Spessartine 1.802 / 3.9
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
Evidence and sources
Authority basis and clause sources
Sources
- CIBJO – The World Jewellery Confederation. Gemmological Laboratories Book (Blue Book), Gemmological Commission 2024-1.
- CIBJO – The World Jewellery Confederation. The Gemstone Book (Blue Book), 2022.
- SAMR / SAC (China). GB/T 16552—2017 Gems — Nomenclature.
- RRUFF Project, in partnership with the IMA – International Mineralogical Association. IMA Mineral List.
- eCFR (United States). 16 CFR Part 23 — Guides for the Jewelry, Precious Metals, and Pewter Industries.
Further reading
Related entries and topic cluster
Parent entry and related pages on this site. Rows marked “Planned” are suggested new content and have no link yet.
Related-entry tree for Corundum on this site: 18 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (White Sapphire) is marked.
- Corundum
Sub-entries (13)
- Colour-change Sapphire
- Green Sapphire
- Orange Sapphire
- Padparadscha Sapphire
- Pink Sapphire
- Purple Sapphire
- Ruby
Sub-entries (2)
- Lead-Glass-Filled Ruby
- Synthetic Ruby (Synthetic product)
- Sapphire
Sub-entries (2)
- Beryllium-Diffused Sapphire
- Synthetic Sapphire (Synthetic product)
- Star Ruby
- Star Sapphire
- Synthetic Corundum (Synthetic product)
- White Sapphire
- Yellow Sapphire
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Oxide minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the White Sapphire 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. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.