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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Trade name: colour / appearance variety · Natural identity; treatment status unknown
Blue Anhydrite
Also known asAngelite
A commercial colour name for blue anhydrite sold as "Angelite"; the material should be labelled anhydrite, not Gypsum. 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 Blue Anhydrite 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 Blue AnhydriteCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness of Blue AnhydriteEach value with its source and check date
- Blue Anhydrite in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Has any of GIA, FTC, CIBJO or Gem-A put a name for it on record here?
- Name origin and history of Blue AnhydriteWhere the name comes from
- Listing and disclosing Blue AnhydriteThe 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
'Angelite' is a commercial colour name for blue anhydrite (CaSO4); the material itself is the calcium sulfate mineral anhydrite. Anhydrite is a major constituent of sedimentary evaporite deposits and of the cap rocks over salt domes, and it usually results from the dehydration of gypsum; it is also found in igneous rocks, fumarolic deposits, seafloor hydrothermal chimneys, and as an alteration product in hydrothermal mineral deposits. When transparent, anhydrite is colourless or pale blue to violet; included impurities can also make it white, mauve, gray, pale brown or rose, and it is this pale blue shade that the name 'Angelite' refers to. The word anhydrite derives from the Greek for 'without water', contrasting with the hydrous calcium sulfate mineral (gypsum). Note: no definition of the name 'Angelite' was found among the cited authoritative sources.
Scope: Applies to the naming boundary of angelite as a trade colour name for blue anhydrite, and an overview of the formation, composition and colour of anhydrite; a definition of the name 'Angelite' is lacking in the cited sources (flagged as a grade C gap).
Sources Handbook of Mineralogy
Where it forms
Sedimentary evaporite deposits and the cap rocks above salt domes (commonly formed by dehydration of gypsum).
Sources Handbook of Mineralogy
Igneous rocks, fumarolic deposits and seafloor hydrothermal chimneys; an alteration product in hydrothermal mineral deposits.
Sources Handbook of Mineralogy
How it forms, step by step
In evaporite settings or salt-dome cap rocks, gypsum dehydrates to form anhydrite.
Sources Handbook of Mineralogy
Anhydrite can also form in igneous, fumarolic and seafloor hydrothermal settings.
Sources Handbook of Mineralogy
Transparent anhydrite can be pale blue or violet, giving the blue appearance of "Angelite".
Sources Handbook of Mineralogy
Link to appearance
When transparent, anhydrite can be pale blue or violet; impurities may also turn it white, mauve, gray, pale brown or rose. The name 'Angelite' is used for pale-blue anhydrite.
Sources Handbook of Mineralogy
Timescale
The source states no absolute timescale for anhydrite formation.
Sources Handbook of Mineralogy
Related base materials
- Anhydrite (CaSO4): Angelite is a commercial colour name for blue anhydrite; the bulk of the material is anhydrite
Supporting findings
Anhydrite is a major component of sedimentary evaporite deposits and of the cap rocks above salt domes, commonly formed by dehydration of gypsum; it also occurs in igneous rocks, fumarolic deposits and seafloor hydrothermal chimneys, and as an alteration product in hydrothermal mineral deposits.
Evidence grade BScope: Occurrence/genesis of the species.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
South America
- Morococha, Junín, PeruHoM lists an anhydrite specimen locality and does not mention angelite
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
When transparent, anhydrite is colourless or pale blue to violet; included impurities can also make it white, mauve, gray, pale brown or rose, and it is this pale blue shade that the name 'Angelite' refers to.
Evidence grade BScope: A colour description; the colouring agent is not given.
Sources Handbook of Mineralogy
Where the name comes from
The origin of the trade name angelite itself is not given in the cited sources. The etymology below belongs to the parent mineral anhydrite, whose name derives from the Greek for "without water", in contrast to hydrous calcium sulfate minerals (given as "contast" by an OCR error; should read "contrast"). This etymology belongs to the parent mineral, not to the trade name angelite.
Evidence grade BScope: The etymology explains only the origin of the name; it does not establish the material's composition, locality, naturalness, or treatment.
Sources Handbook of Mineralogy
Other research findings
"Angelite" is a commercial colour name for blue anhydrite (CaSO4), the material being anhydrite; the cited authoritative sources do not define the name "Angelite", so it has no authoritative mineralogical definition and does not constitute an identifiable material type.
Evidence grade CScope: Based only on the cited authoritative sources; where they are silent the gap is stated, not filled from commercial sites.
Sources Handbook of Mineralogy
Anhydrite is anhydrous calcium sulfate, CaSO4; its name comes from the Greek for "without water", in contrast to the hydrous calcium sulfate (gypsum).
Evidence grade BScope: Composition and the origin of the name.
Sources Handbook of Mineralogy
"Angelite" is not a variety of gypsum; the commercial colour name may be used once the material has been identified as anhydrite.
Evidence grade BScope: Naming and material-classification statement.
Sources Handbook of Mineralogy
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The name "Angelite" does not appear in the authoritative sources consulted, so the name itself rests on evidence level C only; this account draws on a source on the mineral anhydrite.
- No absolute age for anhydrite formation, and no colouring agent for its colour, are given by the source.
- The source is a mineralogical handbook (level B), not a peer-reviewed paper.
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
- Blue anhydrite (trade name: Angelite)
GB/T 16552—2017 5.1.1 c)
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
"Blue Anhydrite (trade name: Angelite)" is a market name rather than a mineral species name; before using it, verify: Industry-wide term that does not denote a single species.
What this means for you
Before buying, check the recommended listing name "Blue anhydrite (trade name: Angelite)" 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
- 2026-09-01
Trade-name ruling
- Industry-wide term that does not denote a single species.
- Suggested listing name
- Blue anhydrite (trade name: Angelite)
Care and wear
Care
Blue Anhydrite — care (light): under anhydrite, the Oxford Mineral Susceptibility Database records a light-induced colour change in which blue fades to white; the entry covers the mineral anhydrite and does not mention the trade name Angelite.
Mineral Sensitivity Database, Oxford (2021)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- K. Royce, “The Mineral Susceptibility Database” (MSD-2021.06), University of Oxford (2021), doi:10.5287/bodleian:r17kVJb7d: Section: main text (locator checked 2026-10-06)
- Fact checked on
- 2026-10-06
Blue Anhydrite — care (storage): the database states that anhydrite hydrates to gypsum once relative humidity exceeds roughly 66% at 15 °C, 70% at 20 °C or 75% at 25 °C.
Mineral Sensitivity Database, Oxford (2021)
- Treatment state
- any treatment state
Source & check 2026-10-06
- Source
- K. Royce, “The Mineral Susceptibility Database” (MSD-2021.06), University of Oxford (2021), doi:10.5287/bodleian:r17kVJb7d: Section: main text (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.
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Durability and wearing
Numbers in curly braces, such as {111}, are crystallographic face symbols (Miller indices): each marks a set of crystal faces or cleavage planes. They are reproduced as written in the cited source.
Cleavage
{010} perfect; {100} nearly perfect; {001} good to imperfect
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Blue Anhydrite, the name register records "Angelite" and "blue anhydrite", for which no restriction on use as a name is recorded.
Standard and listing namesThe suggested listing name for Blue Anhydrite is Blue Anhydrite (trade name: Angelite). The original does not list a corresponding national-standard name, and the basic name must be determined by identification under GB/T 16552—2017. Trade and mineralogical namesThe market name is Angelite, with the synonym blue anhydrite; Angelite is not a separate mineral species, nor a variety of gypsum. Names in four languagesNames are given in four languages: Simplified Chinese, Traditional Chinese, English (Blue Anhydrite, trade name: Angelite) and Japanese (blue anhydrite, with the market name Angelite in katakana). The entry's own Japanese name is that same form, and Japan's GSJ wording for this name is not yet verified by this site. Institution usageOf GIA, FTC, CIBJO and Gem-A, the FTC and CIBJO texts on file have no wording for this name (checked), while GIA and Gem-A are not yet verified; bodies without a recorded wording show the entry's own English name, which does not represent their position. Trade and mineralogical namesThe qualifier attached to the English name, (trade name: Angelite), comes from the entry's own English name.
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 (2) | ||||
| AngeliteEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited); Note: Related high-risk name “Angelite”: angelite is neither a mineral species of its own nor a variety of gypsum. |
| blue anhydriteEnglish | 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
- 青色硬石膏（市場名：エンジェライト） (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)
- basic name to be determined by testing (GB/T 16552—2017 §5.1.1 c))
- Mineralogical name
- Blue anhydrite (CaSO4) sold as Angelite
- Trade names and synonyms
- Angelite (market name)
Four-language names
- 简体中文
- 天使石
- 繁體中文
- 天使石
- English
- Blue Anhydrite (trade name: Angelite)
- 日本語
- 青色硬石膏（市場名：エンジェライト）
Qualifiers stripped from the headline name
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Sulfate minerals
- Identity tier
- Trade name: colour / appearance variety
- Mineral chemical class
- Sulfates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The registered material facts for Blue Anhydrite are: Mohs hardness 3–3.5; cleavage perfect, tenacity brittle, with cleavage and tenacity marked as untreated. Site note: the cited clause covers the whole species, of which Blue Anhydrite is only one variety, so the registered values are given from the clause for the whole species rather than for the Blue Anhydrite variety alone.
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”.
Durability
Blue Anhydrite — Mohs hardness: 3–3.5
Handbook of Mineralogy
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))
- Qualification
The clause we cite covers the whole species. This entry is only one variety of it.
Source & check 2026-09-20
- Source
- Handbook of Mineralogy — Anhydrite (Mineral Data Publishing): p. 1, Physical Properties (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Blue Anhydrite — toughness: cleavage perfect; tenacity brittle
Handbook of Mineralogy
- Treatment state
- untreated
- Qualification
The clause we cite covers the whole species. This entry is only one variety of it.
Source & check 2026-09-20
- Source
- Handbook of Mineralogy — Anhydrite (Mineral Data Publishing): p. 1, Physical Properties (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
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). Mineral specimen m01890: Anhydrite.
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 | Sulfate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Blue Anhydrite 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.