On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Sinhalite
A mineral species basic name listed in GB/T 16552-2017 Appendix A.1; individual specimens still need to be identified. 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 Sinhalite 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 SinhaliteHow far lab testing can go and whether a synthetic exists
- Caring for and wearing SinhaliteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of SinhaliteEach value with its source and check date
- Sinhalite 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?
- Name origin and history of SinhaliteWhere the name comes from
- Listing and disclosing SinhaliteThe listing name to use; what must be disclosed before sale
- Standard clauses that define SinhaliteWhich 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
Sinhalite is an orthorhombic and rare magnesium aluminium oxide that carries boron, MgAlBO4. The mineral data sheet describes it as an accessory mineral in boron-rich skarns at the boundary between limestone and granite or gneiss, where it is accompanied by spinel, serendibite, ludwigite and warwickite. Gem-quality material is found chiefly as detrital grains in gem gravels, for instance in Sri Lanka's Ratnapura district and at Mogok in Myanmar. Boron-rich fluids operating under contact-metamorphic conditions govern its formation.
Scope: Applies to the composition and occurrence of sinhalite as an accessory mineral of boron-rich skarns and as an alluvial gem; does not include geochronology of specific deposits.
Sources Handbook of Mineralogy
Where it forms
Boron-rich skarns where limestone meets granite or gneiss
Sources Handbook of Mineralogy
Gem gravels (placers) of Sri Lanka and Mogok, Myanmar
Sources Handbook of Mineralogy
How it forms, step by step
At the contact of limestone with granite or gneiss, contact metamorphism produces boron-rich skarns.
Sources Handbook of Mineralogy
Boron-rich fluids act within the skarn, and magnesium, aluminium, and boron combine to deposit sinhalite as an accessory mineral.
Sources Handbook of Mineralogy
Sinhalite is intergrown with spinel, serendibite, and ludwigite.
Sources Handbook of Mineralogy
After weathering, resistant sinhalite is transported and concentrated in gravels as placer material.
Sources Handbook of Mineralogy
Link to appearance
Sinhalite ranges from colorless to pale yellow and brown; when chromian it is brownish pink to pale pink, an important gemological feature, with vitreous luster and transparency.
Sources Handbook of Mineralogy
Timescale
The source does not state an absolute geological timescale for sinhalite formation.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Supporting findings
Sinhalite is a rare accessory phase that develops where boron-rich skarns form at the boundary between limestone and granite or gneiss.
Evidence grade BScope: Describes contact-metamorphic boron-rich settings; not all occurrences.
Sources Handbook of Mineralogy
Sinhalite is associated with spinel, serendibite, ludwigite, and warwickite.
Evidence grade BScope: A specific skarn association, not universal.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Behara, Anosy, Madagascar
Sources Mindat: Sinhalite
- Kwakonje area, Handeni District, Tanzania
Sources Handbook of Mineralogy
Asia
- Ratnapura, Sri LankaGem gravels
Sources Handbook of Mineralogy
- Mogok area, MyanmarGem gravels
Sources Handbook of Mineralogy
- Tayozhnoye iron deposit, Sakha, Russia
Sources Handbook of Mineralogy
- Huayuangou boron deposit, Kuandian, Liaoning, China
Sources Handbook of Mineralogy
- Sri LankaType locality recorded only to country level
Sources Mindat: Sinhalite
North America
- Bodnar quarry, Hamburg, Sussex County, New Jersey, United States
Sources Handbook of Mineralogy
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
Chromian sinhalite is brownish pink to pale pink, with chromium causing the pink hue.
Evidence grade BScope: Applies to chromian material only; not colorless or yellow samples.
Sources Handbook of Mineralogy
Where the name comes from
The English name sinhalite derives from Sinhala, the Sanskrit name for Ceylon.
Evidence grade BScope: Etymology explains the origin of the name only; it does not establish the material's composition, locality, naturalness, or treatment.
Sources Handbook of Mineralogy
Other research findings
Sinhalite is a boron-bearing magnesium aluminium oxide, MgAlBO4, orthorhombic.
Evidence grade BScope: Ideal end-member composition; Fe and other elements may substitute.
Sources Handbook of Mineralogy
The name sinhalite derives from Sinhala, the Sanskrit name for Ceylon.
Evidence grade BScope: Etymology only.
Sources Handbook of Mineralogy
In the CIBJO standard, Sinhalite is listed as an independent mineral species / gemstone name, marked no treatment (always).
Evidence grade AScope: Confirms nomenclature and identity level only.
Sources CIBJO Gemstone Book 2022
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The data sheet gives no absolute ages for sinhalite formation.
- The specific P-T conditions and fluid chemistry of sinhalite formation in boron-rich skarns are not quantified in this source.
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
- Sinhalite
GB/T 16552—2017 Table A.1 “Sinhalite” · IMA Mineral List 2026-07 “Sinhalite”
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
Sinhalite is Sinhalite; use "Sinhalite" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 硼铝镁石 (Sinhalite)
What this means for you
Before buying, check the recommended listing name "Sinhalite" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- Last reviewed
- 2026-09-01
Care and wear
Normal care for every gemstone (CIBJO Gemstone Book §6.1), in brief:
- Handle it gently.
- Store pieces apart when not worn, so they cannot scratch each other.
- Clean with warm soapy water and a soft brush.
- Use ultrasonic cleaners only with caution.
The §6.1 wording and the full list of §6.2 special-care letters cited on this page are on the general gem care page.
Care
Sinhalite — care (cleaning): Some stones are susceptible to damage from ultrasonic cleaning. Do not expose them to ultrasonic cleaning.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code j
- Treatment state
- any treatment state
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Sinhalite, p.76; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
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
CleaningSinhalite must not be cleaned ultrasonically; the source is the CIBJO Gemstone Book (2022), and this applies regardless of treatment status. General careIn addition, general care that applies to all gemstones, and the table of special-care letters cited in each item, are in the general care part of the material entry index page.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | care (cleaning) |
Durability and wearing
VerifyNames, standards, technical facts, clauses and sources
Names
Standard and listing namesThe Chinese formal name for Sinhalite comes from GB/T 16552—2017 Table A.1; the suggested listing name is Sinhalite; the mineralogical name and the English description are both Sinhalite. Names in four languagesThe four-language names cover Simplified Chinese, Traditional Chinese, English (Sinhalite) and Japanese. Institution usageOn authority wording, CIBJO has the wording Sinhalite on record (CIBJO Gemmological Laboratories Book 2024); the FTC text on file has no wording for this name (checked); GIA and Gem-A are unchecked, and bodies without a record show the entry's own English name, which does not represent their position. Japanese namesThe GSJ (Japan) wording is not yet verified by this site; the entry's own Japanese name is shown.
- GSJ (Japan) formal name
- シンハライト (not yet checked for this body — the entry's own Japanese name is shown)
- Chinese formal name
- 硼铝镁石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Sinhalite
Four-language names
- 简体中文
- 硼铝镁石
- 繁體中文
- 硼鋁鎂石
- English
- Sinhalite
- 日本語
- シンハライト
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Borate and tungstate minerals
- Identity tier
- Mineral species
- Mineral chemical class
- Borates and tungstates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
Among the registered material facts for Sinhalite, composition is MgAlBO4, which may contain elements such as Fe; structure is crystalline, orthorhombic; Mohs hardness is 6–7 with imperfect cleavage, and this site notes that hardness alone is not enough to judge durability. Density is 3.46–3.5 g/cm³, derived from the cited clause's 3.48 with a stated tolerance of ±0.02; refractive index is 1.665–1.712, derived from the cited clause's 1.668–1.707 with a stated tolerance of +0.005, −0.003; birefringence is 0.036–0.039; the optic character is anisotropic, biaxial, negative; transparency is transparent to translucent. Where the treatment state is untreated, pleochroism is moderate, light brown and dark brown; magnification shows gas-liquid inclusions, mineral inclusions, growth striations and obvious doubling (birefringence); lustre is vitreous; and body colour is greenish yellow to brownish yellow, brown and other colours, rarely light pink. GB/T and CIBJO list the same colours. The UV-visible spectrum shows absorption peaks at 493nm, 475nm, 463nm and 452nm, and the mid-infrared region shows the characteristic infrared absorption bands of sinhalite.
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
Sinhalite — nomenclature status: IMA status G: grandfathered (described before the IMA existed, and generally regarded as a valid species).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Sinhalite — composition (chemistry): MgAlBO4, elements such as Fe may be contained.
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — composition (phase): sinhalite
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Sinhalite — 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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — structure (crystal system): orthorhombic
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — structure (crystal habit): columnar
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Sinhalite — Mohs hardness: 6–7
GB/T 16553—2017
Reference points on this site: Talc 1–3, Fluorite 4, Apatite 5–5.5, Orthoclase 6–6.5, Topaz 8, Diamond 10 (Source: GB/T 16553—2017); Gypsum 1.5–2, Calcite 3, Quartz 7 (Source: Handbook of Mineralogy); Corundum 9 (Source: GIA Gem Encyclopedia (care guide))
- Does this standard apply
- applies to this entry
- General note
- hardness only, not durability
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — cleavage: imperfect
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Physical properties
Sinhalite — density: 3.46–3.5 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 3.48, with a stated tolerance of ±0.02. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Sinhalite — optic character: biaxial, optically negative (anisotropic)
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — refractive index: 1.665–1.712
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.668–1.707, with a stated tolerance of +0.005 / -0.003. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — birefringence: 0.036–0.039
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — transparency: transparent to translucent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Sinhalite — pleochroism: moderate, light brown to dark brown
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — fluorescence (overall): none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — spectrum (UV-visible): 493 nm absorption peak; 475 nm absorption peak; 463 nm absorption peak; 452 nm absorption peak.
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): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — spectrum (infrared): Sinhalite's own diagnostic bands are seen in the mid-IR
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Sinhalite — magnification: gas-liquid inclusions, mineral inclusions, growth striations, obvious birefringence.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
body colour2 sources compared
Sinhalite — body colour: green-yellow to brownish yellow and brown; light pink (rare).
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 Peridot, Zoisite, Andalusite and other variety clauses also name yellow or a yellowish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Sinhalite — body colour: Greenish to brownish yellow, brown, rarely light pink.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Chrysoberyl, Peridot, Amblygonite and other entries also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
How the sources relate
- GB/T 16553—2017 and CIBJO Gemmological Laboratories Book 2024
The two entries agree: greenish to brownish yellow and brown, and both note that light pink is rare.
Quality factors
Sinhalite — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.32 (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): 1.688 / 3.48; Closest values: 1Rhodochrosite 1.707 / 3.58, 2Fei Cui / Jadeite Jade 1.683 / 3.35, 3Peridot 1.672 / 3.38, 4Hydrogrossular 1.7 / 3.35, 5Artificial Strontium Aluminate Borate 1.665 / 3.39
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
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: §6.1.74.
How far testing can go
Sinhalite — 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
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Sinhalite is defined directly in the chapter listing and defining gem materials in the CIBJO Gemmological Laboratories Book 2024, under the term Sinhalite; CIBJO lists Sinhalite as a mineral species with IMA status G, with the CIBJO wording quoted in full under Clause-level definitions on this page, and the cross-check result is defined directly by CIBJO, also appearing in the GB/T annex. The IMA mineral list entry is recorded as Sinhalite MgAl(BO4) G 1952, cross-checked against the RRUFF/IMA mineral list master table, with public-domain data.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Sinhalite | 7.2.1.216 | Greenish to brownish yellow, brown, rarely light pink; transparent to translucent | Defined directly by CIBJO; also present in the GB/T annex. |
| Sinhalite | IMA Mineral List entry | Sinhalite MgAl(BO4) G 1952 | Cross-checked against the RRUFF/IMA master mineral list (public domain data). |
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.
- Geological Survey of Japan, AIST (Japan). Museum mineral specimens, browse by classification.
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.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Borate and tungstate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Sinhalite 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.