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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Cassiterite
A tin oxide mineral species with the formula SnO2, fairly dense and often dark; listed as “cassiterite” in Table A.1 of GB/T 16552—2017. 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 Cassiterite forms and what gives its colourFormation setting, process and timescale; where its colour and optical effects come from, each finding graded and sourced
- Caring for and wearing CassiteriteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of CassiteriteEach value with its source and check date
- Cassiterite 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 CassiteriteWhere the name comes from
- Listing and disclosing CassiteriteThe listing name to use; what must be disclosed before sale
- Standard clauses that define CassiteriteWhich 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
Cassiterite is tin dioxide, SnO2; it is tetragonal, belongs to the rutile group, and is tin's principal ore mineral. The data sheet places it in hydrothermal veins of medium to high temperature and in greisen, in rhyolite, granite and granite pegmatite, rarely in contact-metamorphic deposits, and concentrated in extensive alluvial placers. Muscovite, quartz, wolframite, topaz, tourmaline, fluorite, scheelite, lepidolite, molybdenite and arsenopyrite are its common associates, consistent with tin-rich high-temperature magmatic-hydrothermal systems; because it resists weathering, it is subsequently enriched in placers.
Scope: Applies to the composition and occurrence of cassiterite as a tin ore mineral in high-temperature hydrothermal deposits/greisens and placers; does not include geochronology or quantitative ore-forming models of specific deposits.
Sources Handbook of Mineralogy
Where it forms
Greisen bodies, together with hydrothermal veins that formed at medium to high temperature
Sources Handbook of Mineralogy
Rhyolite, granite and granite pegmatite; only rarely contact-metamorphic deposits
Sources Handbook of Mineralogy
Extensive alluvial placers
Sources Handbook of Mineralogy
How it forms, step by step
In tin-rich medium- to high-temperature magmatic-hydrothermal systems, tin is enriched in fluids as complexes.
Sources Handbook of Mineralogy
The fluids migrate along fractures or within the host rock and precipitate tetragonal cassiterite under oxidizing conditions.
Sources Handbook of Mineralogy
Cassiterite is intergrown with quartz, muscovite, wolframite, tourmaline, topaz, and fluorite.
Sources Handbook of Mineralogy
After weathering of primary ore, resistant cassiterite is transported and concentrated into large alluvial placers.
Sources Handbook of Mineralogy
Link to appearance
Cassiterite ranges from black, brownish black, reddish brown, red, yellow, and gray to white, rarely colorless, and is commonly zoned; it has adamantine to adamantine-metallic luster, is very splendent, with high density, high refractive index, and strong birefringence, being usable as a gem when transparent.
Sources Handbook of Mineralogy
Timescale
The source does not state an absolute geological timescale for cassiterite formation.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Supporting findings
Cassiterite is found in hydrothermal veins of medium to high temperature and in greisen, as well as in rhyolite, granite and granite pegmatite, and only rarely in deposits of contact-metamorphic origin.
Evidence grade BScope: A general occurrence summary, not a deposit model.
Sources Handbook of Mineralogy
Cassiterite is concentrated in large alluvial placers after weathering and transport.
Evidence grade BScope: Describes placer concentration; not all cassiterite occurrences.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Africa
- Jos district, NigeriaTin-ore locality
Sources Handbook of Mineralogy
Asia
- Yunling, Yongde County, Yunnan, ChinaDescribed as a significant source of gem-quality cassiterite
Sources Gems & Gemology Summer 2024
- Amo, Ximeng County, Yunnan, China
Sources Gems & Gemology Summer 2024
Europe
- Cínovec, CzechiaTin-ore locality
Sources Handbook of Mineralogy
South America
- Viloco deposit, La Paz, BoliviaWell-known source of gem-quality cassiterite
Sources Gems & Gemology Summer 2024
Oceania
- New England Ranges, New South Wales, AustraliaTin-ore locality
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 the origin determination guide and the overview of recorded localities.
Causes of colour and optical effects
Cassiterite has adamantine luster, high density, and high refractive index, and transparent material is usable as a gem.
Evidence grade BScope: Describes luster and physical appearance; the specific cause of color is not explained.
Sources Handbook of Mineralogy
Where the name comes from
The English name cassiterite derives from the Greek for “tin.”
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
Cassiterite is tin dioxide, SnO2, tetragonal, in the rutile group, and the principal ore mineral of tin.
Evidence grade BScope: Ideal composition; minor Fe, Nb, Ta, and W may be present.
Sources Handbook of Mineralogy
The name cassiterite is from the Greek for tin.
Evidence grade BScope: Etymology only.
Sources Handbook of Mineralogy
In the CIBJO standard, Cassiterite is listed as a mineral species / gemstone name, marked no treatment (almost 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 cassiterite formation.
- The specific cause of cassiterite's color (trace elements or band structure) is not explained in this source.
- The specific P-T conditions and ages of primary deposits 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
- Cassiterite
GB/T 16552—2017 Table A.1 “Cassiterite” · IMA Mineral List 2026-07 “Cassiterite”
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
Cassiterite is Cassiterite (SnO2); use "Cassiterite" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 锡石 (Cassiterite)
What this means for you
Before buying, check the recommended listing name "Cassiterite" 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
Cassiterite — 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, Cassiterite, p.38; §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
CleaningThe care (cleaning) conclusion for Cassiterite is that it must not be cleaned ultrasonically, in any treatment state, whether treated or untreated; it comes from the care item in the Cassiterite row of the CIBJO Official Gemstone Book (2022) and answers whether ultrasonic cleaning is safe. General careGeneral care that applies to all gemstones, and the full table of special-care letters cited, are in the general care section of the materials 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
Toughness
Brittle
Fracture
Subconchoidal to uneven
Sources Handbook of Mineralogy
VerifyNames, standards, technical facts, clauses and sources
Names
Standard and listing namesThe Chinese standard name for Cassiterite comes from GB/T 16552—2017 Table A.1, and the suggested listing name is Cassiterite. Trade and mineralogical namesThe mineralogical name is Cassiterite (SnO2). Names in four languagesNames are registered in Simplified Chinese, Traditional Chinese, English (Cassiterite) and Japanese; the GSJ (Japan) formal name is cassiterite. Institution usageOn authority wording, CIBJO records Cassiterite (CIBJO Gemmological Laboratories Book 2024); the FTC text on file has no wording for this name (checked); GIA and Gem-A are unchecked. Bodies without a recorded wording show the English name of Cassiterite, which does not represent the position of those bodies.
- GSJ (Japan) formal name
- 錫石
- Chinese formal name
- 锡石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Cassiterite (SnO2)
Four-language names
- 简体中文
- 锡石
- 繁體中文
- 錫石
- English
- Cassiterite
- 日本語
- キャシテライト／錫石
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 species
- Mineral chemical class
- Oxides / hydroxides
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
Material facts for Cassiterite are registered item by item: chemical composition SnO2, possibly containing Fe, Nb, Ta and other elements, phase cassiterite; crystalline, tetragonal, with a tetragonal pyramidal habit and geniculate (knee-shaped) twins; Mohs hardness 6–7, with two imperfect cleavages; density 6.87–7.03 g/cm³, worked out from the cited clause's 6.95 with a stated tolerance of ±0.08. Optically, Cassiterite is anisotropic, uniaxial, optically positive; refractive index 1.991–2.102, worked out from the cited clause's 1.997–2.093 with a stated tolerance of +0.009, −0.006; birefringence 0.096–0.098; dispersion 0.071; transparency transparent to opaque. Untreated Cassiterite shows weak to moderate pleochroism in light to dark brown, no fluorescence, and under magnification gas-liquid inclusions, mineral inclusions, growth striations, colour zoning and pronounced doubling (high birefringence); the lustre is adamantine to subadamantine. Nomenclature status is IMA status G: grandfathered. Site note: hardness alone is not enough to judge durability.
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
Cassiterite — 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
Cassiterite — composition (chemistry): SnO2, elements such as Fe,Nb and Ta 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — composition (phase): cassiterite
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Cassiterite — 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — structure (crystal system): tetragonal
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — structure (crystal habit): tetragonal pyramids; knee-shaped (geniculate) twins
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Durability
Cassiterite — 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — cleavage: imperfect in two directions
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Physical properties
Cassiterite — density: 6.87–7.03 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 6.95, with a stated tolerance of ±0.08. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Cassiterite — optic character: uniaxial, optically positive (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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — refractive index: 1.991–2.102
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.997–2.093, with a stated tolerance of +0.009 / -0.006. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — birefringence: 0.096–0.098
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — dispersion: 0.071
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — transparency: transparent to opaque.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Cassiterite — pleochroism: weak to moderate, light 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — spectrum (UV-visible): non-characteristic
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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — spectrum (infrared): Sn-O vibration produces the diagnostic bands 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Cassiterite — magnification: gas-liquid inclusions, mineral inclusions, growth striations, color band, pronounced doubling (high 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): §5.1.39 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
body colour2 sources compared
Cassiterite — body colour: dark brown to black, yellowish brown, yellow, colorless, etc.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- Qualification
In chapter 5 of GB/T 16553—2017, the colour entries of Epidote, Phenakite, Dolomite and other variety clauses also name brown or a brownish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.39 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Cassiterite — body colour: Dark brown to black, yellowish brown, colourless banded with brown.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Andradite, Bytownite, Danburite and other entries also name brown or a brownish 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
Both list dark brown to black, yellowish brown and colourless. GB/T 16553—2017 also lists yellow; the CIBJO Gemmological Laboratories Book describes the colourless material as banded with brown.
Quality factors
Cassiterite — quality factor (lustre): adamantine to subadamantine
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.39 (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): 2.046 / 6.95; Closest values: 1Artificial Gadolinium Gallium Garnet (GGG) 2 / 7.02, 2Synthetic Cubic Zirconia 2.165 / 5.8, 3Artificial Strontium Titanate 2.409 / 5.13, 4Artificial Yttrium Aluminium Garnet (YAG) 1.833 / 4.55, 5Smithsonite 1.735 / 4.38
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
Clause-level definitions
Cassiterite has a direct definition in the CIBJO Gemmological Laboratories Book 2024 under the term Cassiterite: mineral species cassiterite, IMA status G, with the CIBJO wording quoted in full under Clause-level definitions on this page; the cross-check result is a direct CIBJO definition, also present in the GB/T annex. The IMA Mineral List entry defines Cassiterite SnO2 G 1832 and is cross-checked against the RRUFF/IMA master mineral list (public domain data).
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Cassiterite | 7.2.1.42 | Dark brown to black, yellowish brown, colourless banded with brown; transparent to opaque | Defined directly by CIBJO; also present in the GB/T annex. |
| Cassiterite | IMA Mineral List entry | Cassiterite SnO2 G 1832 | 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.
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| Page | Content | Status |
|---|---|---|
| Browsing family | Oxide minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Cassiterite 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.