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Natural inorganic gem materials · Mineral species · Natural identity; treatment status unknown
Hemimorphite
A silicate mineral species listed in GB/T 16552-2017 Annex A.2; blue hemimorphite on the market may be treated or mixed with other minerals. 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 Hemimorphite 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 HemimorphiteDurability indicators and wearing advice
- Hardness, density and refractive index of HemimorphiteEach value with its source and check date
- Hemimorphite 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 HemimorphiteWhere the name comes from
- Listing and disclosing HemimorphiteThe listing name to use; what must be disclosed before sale
- Standard clauses that define HemimorphiteWhich 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
Hemimorphite is an orthorhombic zinc silicate species with ideal composition Zn4Si2O7(OH)2·H2O. It is a secondary mineral typical of the oxidized (supergene) zone of zinc-bearing deposits, precipitating where zinc-bearing solutions react in a silicate environment; it commonly forms fan-shaped, botryoidal, stalactitic or fibrous aggregates and shows hemimorphic symmetry.
Scope: Applies to the genesis and occurrence of natural hemimorphite as a zinc silicate mineral species; does not cover synthetics or artificial imitations.
Sources Handbook of Mineralogy
Where it forms
The supergene, or oxidized, zone in deposits of zinc-bearing minerals
Sources Handbook of Mineralogy
Associated minerals: chrysocolla, hydrozincite, rosasite, aurichalcite, calcite, anglesite, cerussite, galena, sphalerite, smithsonite
Sources Handbook of Mineralogy
How it forms, step by step
A primary zinc-bearing sulfide ore body (e.g. sphalerite) forms.
Sources Handbook of Mineralogy
The ore body is oxidized and weathered, releasing zinc into solution.
Sources Handbook of Mineralogy
Zinc-bearing solutions react with a silicate environment, precipitating hemimorphite in the oxidized zone.
Sources Handbook of Mineralogy
Fan-shaped, botryoidal, stalactitic or fibrous aggregates form, with doubly-terminated crystals showing hemimorphism.
Sources Handbook of Mineralogy
Link to appearance
Hemimorphite is commonly colourless or white, and may be pale blue, pale green, gray or brown from impurities; it shows vitreous to subpearly to adamantine, and rarely silky, lustre. It is strongly pyroelectric and may fluoresce bluish under SW UV; its silky/fibrous look reflects its radiating aggregate habit.
Sources Handbook of Mineralogy
Timescale
The source states no absolute geological timescale for hemimorphite formation.
Sources Handbook of Mineralogy
Supporting findings
As a secondary mineral, hemimorphite characteristically occurs in the oxidized, or supergene, zone of deposits that carry zinc.
Evidence grade BScope: Describes hemimorphite's secondary origin and setting.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Nerchinsk, Siberia, Russia
Sources Handbook of Mineralogy
- Tchah Kuh, Esfahan, Iran
Sources Handbook of Mineralogy
Europe
- Băiţa mining district, Nucet, Bihor County, Romania
Sources Mindat: Hemimorphite
- Banská Štiavnica, Slovakiaold name Schemnitz given
Sources Handbook of Mineralogy
- Caldbeck Fells, Cumbria, England, United Kingdom
Sources Handbook of Mineralogy
- Moresnet, Belgium
Sources Handbook of Mineralogy
- Freiberg, Saxony, Germany
Sources Handbook of Mineralogy
- Altenberg, Saxony, Germany
Sources Handbook of Mineralogy
- Sa Duchessa mine, Oridda district, Sardinia, Italy
Sources Handbook of Mineralogy
North America
- Franklin and Sterling Hill, Sussex County, New Jersey, United States
Sources Handbook of Mineralogy
- Bisbee, Arizona, United States
Sources Handbook of Mineralogy
- 79 mine, Gila County, Arizona, United States
Sources Handbook of Mineralogy
- Emma mine, Little Cottonwood Canyon, Utah, United States
Sources Handbook of Mineralogy
- Leadville, Lake County, Colorado, United States
Sources Handbook of Mineralogy
- Elkhorn mine, Elkhorn district, Montana, United States
Sources Handbook of Mineralogy
- Santa Eulalia, Chihuahua, Mexico
Sources Handbook of Mineralogy
- Ojuela mine, Mapimí, Durango, Mexico
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
Hemimorphite's pale blue, pale green, gray and brown colouration comes from impurities; the mineral itself is colourless or white.
Evidence grade BScope: Describes impurity-driven colour; specific impurity elements are not quantified.
Sources Handbook of Mineralogy
Where the name comes from
The name hemimorphite is in allusion to the mineral's hemimorphic morphology, i.e. crystal forms whose two ends along a direction differ.
Evidence grade BScope: The etymology explains the origin of a name only; it does not attest composition, locality, naturalness or treatment.
Sources Handbook of Mineralogy
Other research findings
Hemimorphite is an orthorhombic zinc silicate species with ideal composition Zn4Si2O7(OH)2·H2O.
Evidence grade BScope: Species-level composition and crystal-system fact.
Sources Handbook of Mineralogy
Doubly-terminated hemimorphite crystals show hemimorphism, the property for which the mineral is named.
Evidence grade BScope: Concerns crystal morphology and naming only; not genesis.
Sources Handbook of Mineralogy
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The source is a mineralogical data sheet and gives no absolute geological timescale for hemimorphite formation.
- The source does not quantify the specific impurity elements responsible for hemimorphite's colour.
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
- Hemimorphite
GB/T 16552—2017 Table A.2 “Hemimorphite” · IMA Mineral List 2026-07 “Hemimorphite”
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
Hemimorphite is Hemimorphite; use "Hemimorphite" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.2, row 异极矿 (Hemimorphite)
What this means for you
Before buying, check the recommended listing name "Hemimorphite" 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
No institutional care guidance is registered for this material yet; below are its durability indicators and general guidance.
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.
Toughness
Brittle
Cleavage
Perfect on {110}; poor on {101}
Daily wear
Mohs 4.5–5, medium-to-low, usable ornamentally; it has perfect {110} cleavage and is brittle, so impact can split it; the main risks are breakage from knocks, abrasion and scratching.
Care
Clean with warm water, mild soap and a soft brush, then rinse and dry; because of perfect {110} cleavage and brittleness, avoid ultrasonic/steam cleaning, impact and sudden temperature change (basis: source records perfect {110} cleavage and brittle tenacity).
General guidance: LumaLark's general guidance inferred from the material's properties (hardness, toughness, cleavage); not text from the cited source, and not a guarantee for any specific piece.
Scope: This field describes the general physical properties of hemimorphite as a material; it makes no durability or safety promise for any specific finished product. Durability of treated (e.g. filled, dyed, coated) or assembled/composite pieces must be assessed separately for the individual item.
VerifyNames, standards, technical facts, clauses and sources
Names
Standard and listing namesThe Chinese formal name for Hemimorphite comes from GB/T 16552—2017 Table A.2; the mineralogical name and the English name are both Hemimorphite, and the suggested listing name is Hemimorphite. Names in four languagesNames are given in four languages: Simplified Chinese, Traditional Chinese, English (Hemimorphite) and Japanese (a katakana transliteration and a kanji name); Japan's GSJ formal name is the kanji form. Institution usageOn authority wording, GIA and Gem-A are unchecked; the FTC and CIBJO texts on file have no wording for this name (checked), and bodies without a recorded wording show the entry's own English name, which does not represent their position. Hemimorphite is a natural material within natural inorganic gem materials, with the identity tier mineral species, the mineral chemical class silicates and the browsing family other silicate minerals.
- GSJ (Japan) formal name
- 異極鉱
- Chinese formal name
- 异极矿 (GB/T 16552—2017 Table A.2)
- Mineralogical name
- Hemimorphite
Four-language names
- 简体中文
- 异极矿
- 繁體中文
- 異極礦
- English
- Hemimorphite
- 日本語
- ヘミモルファイト／異極鉱
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Other silicate minerals
- Identity tier
- Mineral species
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The chemical composition of Hemimorphite is registered as Zn4[Si2O7](OH)2·H2O; structure crystalline or crystalline aggregate, orthorhombic, with mostly tabular crystals and aggregates mostly tabular-granular with a radial structure. Mohs hardness 4–5, with the site note that hardness alone is not enough to judge durability; density 3.4–3.5 g/cm³. Optical character biaxial, positive, commonly an anisotropic aggregate; refractive index 1.614–1.636; birefringence 0.022, where the site note explains that the clause has finer sub-ranges and the overall value is registered. Untreated, the body colour is colourless or light blue, and may also be white, grey, light green, light yellow, brown and similar colours; lustre is vitreous, pearly on cleavage surfaces.
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
Hemimorphite — composition (chemistry): Zn4[Si2O7](OH)2 • H2O
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Structure
Hemimorphite — structure (overall): crystalline, or else a crystalline 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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — structure (crystal system): orthorhombic system
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — structure (crystal habit): commonly tabular; aggregates are commonly tabular-granular with a radial structure, and sometimes crust-like, reniform, stalactitic or earthy.
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): §5.2.37 (locator checked 2026-09-22)
- Fact checked on
- 2026-09-22
Durability
Hemimorphite — Mohs hardness: 4–5
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Physical properties
Hemimorphite — density: 3.4–3.5 g/cm³
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Hemimorphite — optic character: biaxial positive; usually behaves as an 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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — refractive index: 1.614–1.636
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — birefringence: 0.022
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — 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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — fluorescence (overall): generally 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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — 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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — spectrum (infrared): Mid-IR absorption follows the pattern typical of hemimorphite
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — magnification: granular structure, radial structure
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): §5.2.37 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Hemimorphite — body colour: colorless or pale blue; white, grey, pale green, pale yellow and brown also occur.
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 Iolite, Kyanite, Feldspar and other variety clauses also name colourless.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.37 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Quality factors
Hemimorphite — quality factor (lustre): vitreous; cleavage surfaces show a pearly lustre.
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): §5.2.37 (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): 1.625 / 3.45; Closest values: 1Imperial Topaz 1.623 / 3.53, 2Glass 1.585 / 3.4, 3Synthetic Jadeite 1.66 / 3.34, 4Artificial Strontium Aluminate Borate 1.665 / 3.39, 5Peridot 1.672 / 3.38
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
Hemimorphite is listed in GB/T 16552-2017 Annex A under the term Hemimorphite; the cross-check shows it is listed directly by GB/T, and CIBJO carries no standalone entry under the same name. Hemimorphite is also listed in the IMA Mineral List entry, again under the term Hemimorphite, with the definition Hemimorphite Zn4(Si2O7)(OH)2·H2O A 1962 s.p., cross-checked against the RRUFF/IMA master mineral list using public domain data.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Hemimorphite | GB/T 16552-2017 Annex A | Hemimorphite | Listed directly by GB/T; CIBJO carries no standalone entry under the same name. |
| Hemimorphite | IMA Mineral List entry | Hemimorphite Zn4(Si2O7)(OH)2·H2O A 1962 s.p. | 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 | Other silicate minerals | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Hemimorphite 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.