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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
Andesine
Also known asRed Andesine (conditional name)
A plagioclase feldspar with a composition in the middle of the series. Andesine sold in China is often diffusion-treated Labradorite, and the cause of its colour needs laboratory evidence. Also known as Red Andesine. 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 Andesine 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 AndesineHow far lab testing can go
- Treatments and enhancements of AndesineThe enhancements and treatments the GB/T and JJA/AGL tables list
- Caring for and wearing AndesineCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of AndesineEach value with its source and check date
- Andesine 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 AndesineThe listing name to use; what must be disclosed before sale
- Standard clauses that define AndesineWhich 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
Andesine is an intermediate variety of the plagioclase solid-solution series defined by An content (about An30-50 by convention), lying between oligoclase and labradorite; it is not an independent mineral species but a compositional-range name within the plagioclase continuous solid solution (albite NaAlSi3O8 - anorthite CaAl2Si2O8). The 'red andesine' on the market has been widely controversial: extensive studies of composition, spectroscopy, appearance, and isotopic properties indicated that much red andesine is the product of laboratory copper diffusion into pale yellow andesine (Ab70-50An30-50) from Inner Mongolia; a deposit of natural red andesine in China/Tibet has likewise been reported, though whether it is truly natural has been disputed since 2006. Copper-bearing andesine-labradorite (Ab46-51An46-51Or2-3) can be classified using the Ab-An-Or ternary diagram.
Scope: Applies to the composition and occurrence of natural andesine as the name for the intermediate range of the plagioclase series, and explains the copper-diffusion treatment controversy over 'red andesine'; artificially coloured material is not treated as being of natural origin.
Sources G&G Winter 2022 · G&G Summer 2025 · G&G Spring 2011 +2
- Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine (Gems & Gemology, Winter 2022, Vol. 58, No. 4)
- Structures Behind the Spectacle: A Review of Optical Effects in Phenomenal Gemstones and Their Underlying Nanotextures
- The Chinese Red Feldspar Controversy: Chronology of Research Through July 2009 (Gems & Gemology, Spring 2011, Vol. 47, No. 1)
- Research on Gem Feldspar from the Shigatse Region of Tibet (Gems & Gemology, Summer 2011, Vol. 47, No. 2)
- Sunstone Plagioclase Feldspar from Ethiopia (Gems & Gemology, Spring 2020, Vol. 56, No. 1, Gem News International)
Where it forms
Intermediate-composition magmatic and metamorphic settings: andesine, as an intermediate plagioclase range, occurs in the corresponding igneous and metamorphic rocks.
Sources G&G Winter 2022 · G&G Summer 2025 · G&G Spring 2011 +2
- Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine (Gems & Gemology, Winter 2022, Vol. 58, No. 4)
- Structures Behind the Spectacle: A Review of Optical Effects in Phenomenal Gemstones and Their Underlying Nanotextures
- The Chinese Red Feldspar Controversy: Chronology of Research Through July 2009 (Gems & Gemology, Spring 2011, Vol. 47, No. 1)
- Research on Gem Feldspar from the Shigatse Region of Tibet (Gems & Gemology, Summer 2011, Vol. 47, No. 2)
- Sunstone Plagioclase Feldspar from Ethiopia (Gems & Gemology, Spring 2020, Vol. 56, No. 1, Gem News International)
A gem-treatment setting (for 'red andesine'): pale yellow andesine is colour-modified by laboratory high-temperature copper diffusion to mimic red labradorite-an artificial treatment, not a natural formation setting.
Sources G&G Winter 2022 · G&G Summer 2025 · G&G Spring 2011 +2
- Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine (Gems & Gemology, Winter 2022, Vol. 58, No. 4)
- Structures Behind the Spectacle: A Review of Optical Effects in Phenomenal Gemstones and Their Underlying Nanotextures
- The Chinese Red Feldspar Controversy: Chronology of Research Through July 2009 (Gems & Gemology, Spring 2011, Vol. 47, No. 1)
- Research on Gem Feldspar from the Shigatse Region of Tibet (Gems & Gemology, Summer 2011, Vol. 47, No. 2)
- Sunstone Plagioclase Feldspar from Ethiopia (Gems & Gemology, Spring 2020, Vol. 56, No. 1, Gem News International)
How it forms, step by step
Plagioclase of andesine composition (about An30-50) crystallizes from intermediate plagioclase melts/fluids.
Its range name (andesine) is defined by An content and must be confirmed by compositional analysis.
(For commercial 'red andesine') pale yellow andesine is heated at high temperature in a copper-bearing diffusant so that copper diffuses into the crystal and changes its colour.
Whether material is treated can be distinguished with fluorescence spectroscopy, trace elements, and isotopic analysis rather than appearance alone.
Link to appearance
Andesine is an intermediate compositional range of the plagioclase series; a red appearance can be produced by copper diffusion treatment, resembling natural copper-bearing red labradorite, so colour alone cannot prove origin and treatment testing is needed.
Sources G&G Winter 2022 · G&G Summer 2025 · G&G Spring 2020
- Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine (Gems & Gemology, Winter 2022, Vol. 58, No. 4)
- Structures Behind the Spectacle: A Review of Optical Effects in Phenomenal Gemstones and Their Underlying Nanotextures
- Sunstone Plagioclase Feldspar from Ethiopia (Gems & Gemology, Spring 2020, Vol. 56, No. 1, Gem News International)
Timescale
The sources give time points such as the first appearance of 'red andesine' at the 2006 Tucson gem shows, but no absolute age or duration for andesine crystallization itself.
Sources G&G Winter 2022 · G&G Summer 2025 · G&G Summer 2011
- Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine (Gems & Gemology, Winter 2022, Vol. 58, No. 4)
- Structures Behind the Spectacle: A Review of Optical Effects in Phenomenal Gemstones and Their Underlying Nanotextures
- Research on Gem Feldspar from the Shigatse Region of Tibet (Gems & Gemology, Summer 2011, Vol. 47, No. 2)
Related base materials
- Plagioclase solid-solution series (albite-anorthite): range-of | Andesine is the name of an intermediate range of the plagioclase solid-solution series, defined by An content
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Inner Mongolia, ChinaPale yellow andesine rough, copper-diffused to red before sale.
Sources Gems & Gemology Spring 2011
- Bainang County, Tibet, ChinaNatural origin of the red andesine is disputed; of two sites visited in 2010, one appeared genuine and one could not be confirmed.
Sources G&G Summer 2011 · Gems & Gemology Spring 2011
South America
- Marmato, Colombia
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
Andesine occupies the middle of the plagioclase series (about An30–50), just below the labradorite boundary; in this family the iridescence comes from alternating calcic and sodic submicron lamellae formed by solid-state exsolution (the Bøggild intergrowth), with multilayer interference when lamellae thickness matches visible-light wavelengths. The difference between andesine and labradorite lies mainly in An content and lamellae thickness: the more calcic the composition, the thicker the calcic lamellae and the longer the interference wavelength.
Evidence grade AScope: The cited sources record no iridescence example for andesine itself (they mainly discuss its composition and copper-diffusion treatment); strong labradorescence is placed at An46–60, above andesine's range, so this is only a conservative mechanistic inference.
A separate effect must be distinguished: copper-bearing sunstone (such as andesine–labradorite) produces a golden-to-red sheen/aventurescence through directional reflection by microscopic metallic (copper) inclusions; that is an inclusion-reflection effect, a different mechanism from the exsolution-lamellae interference behind labradorescence.
Evidence grade AScope: Used only to distinguish aventurescence from labradorescence as two mechanisms; it makes no identification claim about copper-diffusion treatment.
Other research findings
Andesine is an intermediate variety of the plagioclase solid-solution series defined by An content, lying between oligoclase and labradorite (about An30-50 by convention); it is not an independent mineral species.
Evidence grade AScope: A range-name statement; the range boundaries are conventional.
Sources G&G Winter 2022 · G&G Summer 2025
A red-and-green andesine variety (Ab70-50An30-50) was unveiled at the 2006 Tucson gem shows; its composition resembles natural Oregon labradorite sunstone, which drew attention to whether its colour origin is natural or treated.
Evidence grade AScope: An event described in reports and a literature review; it does not determine the origin of an individual specimen.
Sources G&G Winter 2022 · G&G Summer 2025
Wide-ranging work on composition, spectroscopy, appearance and isotopic properties showed that a large share of the red andesine sold is produced by diffusing copper in a laboratory into pale yellow andesine originating in Inner Mongolia; copper-bearing flux residues on rough and argon-isotope data demonstrated that the material examined had been heated to a high temperature not long before.
Evidence grade AScope: A conclusion for that study's tested samples (through July 2009); it does not cover the 2010 Tibet expedition samples.
Whether a natural red andesine deposit exists in China/Tibet has been controversial since 2006; initial argon isotope measurements showed some (glass-free) Tibetan andesines had not been heated, but more investigation is needed to establish practical identification criteria.
Evidence grade AScope: An interim conclusion after the 2011 field expedition; the authors explicitly note the method is impractical for laboratories.
Copper-bearing plagioclase of undetermined colour origin classifies as andesine-labradorite (Ab46-51An46-51Or2-3) on the Ab-An-Or ternary diagram, distinct from Oregon and Ethiopian labradorite-bytownite material.
Evidence grade AScope: A compositional classification; it does not resolve whether the undetermined-colour-origin material is natural or treated.
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The sources give no absolute age or duration for andesine crystallization itself.
- The 'red andesine' controversy concerns samples from a specific period (through 2009-2010); this record draws no conclusion about any individual specimen on the market.
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
- Andesine (treatment status must be determined by testing)
16 CFR Part 23 §23.24
Construction or treatment status
Natural identity; treatment status unknown
Treatments recorded for this material: Filled / Fracture-filled (via parent material), Coated (via parent material), Diffusion-treated, Irradiated (via parent material)
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
"Andesine" is a market name rather than a mineral species name; before using it, verify: Laboratory identification required before the name is used.
Evidence
What this means for you
Before buying, check the recommended listing name "Andesine (treatment status must be determined by testing)" 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
- Laboratory identification required before the name is used.
- Suggested listing name
- Andesine (treatment status must be determined by testing)
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
Andesine — 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
- Colours covered
- red andesine only
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Andesine, p.51-52; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Andesine — care (wear): cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code b
- Treatment state
- any treatment state
- Colours covered
- red andesine only
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Andesine, p.51-52; §6.2 b (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
CleaningCare of Andesine: the Andesine row of the CIBJO Gemstone Book (Blue Book, 2022) states that red Andesine must not be cleaned ultrasonically, whatever the treatment state, and that red Andesine fractures easily and should be worn with care, whatever the treatment state. Andesine in colours other than red falls outside these statements. General careGeneral care that applies to all gemstones is 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? | red andesine only: care (cleaning) |
| Wearing limits (knocks, settings) | red andesine only: cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care |
Treatments and identification leads
One row per treatment, with three standards side by side: how often it occurs and how stable it is (CIBJO), its category in GB/T 16552—2017 Table B.1 (this site's paraphrase) and how the JJA/AGL 2025 table lists it. Each CIBJO value links to its entry under “Testing and market”, where the wording and source are given in full.
This table scrolls sideways on narrow screens.
| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| Filling | — | — | Graded — see §5.4.1, Table 1 | — | — |
| Coating | — | — | Treatment | — | — |
| Diffusion | — | — | Treatment | — | — |
| Irradiation | — | — | Treatment | — | — |
| copper diffusion | — | — | — | copper diffusion (green); copper diffusion (red) | — |
“—” means the cited source gives no value for that item, not “none”. Source: GB/T 16552—2017 Table B.1 (row for Feldspar); JJA/AGL 2025
Whether a treatment has to show in the name differs between the two rule sets (this site’s paraphrase):
- GB/T 16552—2017: a method classed as treatment has to be stated in the name itself — the method put before the name, or added in brackets after it; a method classed as optimization does not need to appear in the name, though one marked “Optimization (annotation required)” still has to be noted in the quality documents. Source: §5.4.2.1 a), b); §5.4.2.2 a)
- CIBJO Gemstone Book 2022: no longer splits treatments into ones that need specific disclosure and ones that need only general disclosure: every treatment is to be disclosed, and the seller tells the buyer which treatment was used and what special care it calls for. Source: §4.2.5 Note 2, §4.2.5.1, pp.14–15
What this table covers
What this page can give
- Registered treatments, their stability and how often they occur (see the table above)
- Identification leads for each treatment, for use when sending a stone for testing
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Andesine, the name register records "Red Andesine", for which no restriction on use as a name is recorded (JJA/AGL Gemstone Nomenclature 2025 p.15); one further name in a non-Latin script is listed in the name register below (1 with no restriction recorded on use as a name).
Standard and listing namesThe mineral/material name of Andesine is not listed in Annex A of GB/T 16552—2017 and can be used directly as the name. The suggested listing name is Andesine (treatment status must be identified). Trade and mineralogical namesThe mineralogical name is Andesine. Names in four languagesNames are given in four languages: Simplified Chinese, Traditional Chinese, English (Andesine) and Japanese (a katakana transliteration and a kanji name). Japan's GSJ formal name is the kanji name meaning intermediate feldspar. Institution usageOn authority wording, CIBJO uses Andesine (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 Andesine, which does not represent their position. Japanese namesThe JJA/AGL Gemstone Nomenclature 2025 also registers Red Andesine as a market name, to be matched only once the condition is confirmed. Candidate search termsIts Japanese transliteration serves only as a search candidate.
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 (2) | ||||
| Red AndesineEnglish | market name | matched only once the condition is confirmed | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
| レッド・アンデシンJapanese | transliteration | search candidate only | no restriction recorded | JJA/AGL Gemstone Nomenclature 2025 p.15 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 中性長石
- Mineral / material name (not in GB/T 16552 Annex A; usable directly)
- 中长石 (GB/T 16552—2017 §5.1.1 b))
- Mineralogical name
- Andesine; plagioclase feldspar intermediate variety
- Trade names and synonyms
- Red Andesine (market name; conditional name)
Four-language names
- 简体中文
- 中长石
- 繁體中文
- 中長石
- English
- Andesine
- 日本語
- アンデシン／中性長石
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Feldspar materials
- Identity tier
- Mineral / gemstone variety
- Mineral chemical class
- Silicates
- Construction or treatment status
- Natural identity; treatment status unknown
Treatments listed by standards
GB/T 16552-2017, Annex B, Table B.1
Under the “Feldspar” row of Table B.1: Filling Graded — see §5.4.1, Table 1; Coating Treatment; Diffusion Treatment; Irradiation Treatment. The full row, with the effect column, is on the Feldspar page.
What Table B.1 is, and how the “see 5.4.1” grades are defined: see the GB/T 16552: optimization vs treatment page.
JJA/AGL (Japan) table of principal gem names, 2025
This table scrolls sideways on narrow screens.
| Gem name | Species | Colour | Listed in the table | Notes |
|---|---|---|---|---|
| Andesine | Andesine | white, grey, yellow | an untreated tier is listed | |
| Andesine | Andesine | green | an untreated tier is listed; copper diffusion (Diffusion-treated) | |
| Red Andesine | Andesine | red | an untreated tier is listed; copper diffusion (Diffusion-treated) |
JJA/AGL definitions and nomenclature (2025 revision), table of principal gem names, p.15
How to read the JJA/AGL table: see the Gem treatments page.
What it is and how it's identified
Among the registered material facts for Andesine, the chemical composition is taken from plagioclase (the whole series), lying between NaAlSi3O8 and CaAl2Si2O8; transparency (transparent) and body colour (untreated: colourless, or light yellow through to green, or red, or brownish red through to orange) come from the CIBJO definition of Andesine. Hardness, cleavage, optical character, pleochroism, lustre, density and other properties are taken from feldspar (the whole mineral group), not measured on Andesine alone: Mohs hardness 6–6.5; two directions of perfect cleavage; anisotropic, biaxial, positive or negative; pleochroism usually none (untreated); vitreous lustre (untreated); iridescence, the cat's-eye effect, asterism and aventurescence can all occur; density 2.55–2.75 g/cm³; refractive index 1.508–1.572; birefringence 0.005–0.01. The site note explains that the density, refractive index and birefringence clauses have finer sub-ranges and the overall values are used; on body colour, the colour descriptions of entries such as zircon, grossular and labradorite in chapter 7 of the CIBJO Blue Book also mention colourless.
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 feldspar (the whole mineral group), so they are not repeated on the Andesine page; see the material facts on the Feldspar entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Andesine (how to read class-level values).
Definition
Andesine — composition (chemistry): plagioclase: NaAlSi3O8–CaAl2Si2O8.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- plagioclase (the whole series)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 Chemical composition · Plagioclase (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Structure
Andesine — structure (overall): crystalline
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — structure (crystal system): Moonstone and amazonite belong to the monoclinic or triclinic system; sunstone and labradorite are triclinic.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — structure (crystal habit): Crystals are tabular or stubby prisms; Carlsbad, polysynthetic and gridiron (cross-hatched) twinning are common.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Andesine — Mohs hardness: 6–6.5
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
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andesine — cleavage: two directions of perfect cleavage
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Andesine — density: 2.55–2.75 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Optical
Andesine — optic character: biaxial and anisotropic; optic sign may be either positive or negative.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — refractive index: 1.508–1.572
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andesine — birefringence: 0.005–0.01
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Andesine — transparency: transparent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Andesine — pleochroism: usually absent
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — optical effect (iridescence): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — optical effect (chatoyancy): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — optical effect (asterism): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — optical effect (aventurescence): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Andesine — body colour: Colourless, light yellow to green, red, brownish red to orange.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Zircon, Grossular, Labradorite 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
- CIBJO definitions
- chatoyancy, asterism, aventurescence
Quality factors
Andesine — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- feldspar (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.17 (locator checked 2026-09-26)
- 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): 1.54 / 2.65; Closest values: 1Charoite 1.554 / 2.66, 2Changhua Stone 1.56 / 2.6, 3Shoushan Stone 1.56 / 2.7, 4Balin Stone 1.56 / 2.55, 5Bamboo Coral 1.57 / 2.65
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 CIBJO laboratory protocol covers Andesine under “Feldspar” (§6.1.34): see identification on the Feldspar entry; the required tests are listed on the CIBJO laboratory protocol table for Feldspar.
How far testing can go
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Clause-level definitions
Andesine has a direct clause-level definition in the CIBJO Gemmological Laboratories Book (2024), registered under the English term Andesine; the definition describes it as a plagioclase feldspar whose albite-to-anorthite molar ratio falls within the range given in the original, from roughly equal proportions to albite-dominant. The cross-check shows it is defined directly by CIBJO, and no identically named English entry was found in this edition of the GB/T annex.
This table scrolls sideways on narrow screens.
| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Andesine | 7.2.1.16 | A plagioclase feldspar with an albite : anorthite molar ratio ranging from 50 : 50 to 70 : 30. Colourless, light yellow to green, red, brownish red to orange, transparent | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
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.
- GIA – Gemological Institute of America (United States). Gem Encyclopedia.
- Gem-A – The Gemmological Association of Great Britain (United Kingdom).
- eCFR (United States). 16 CFR § 23.24 — Disclosure of treatments to gemstones. In: 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 Feldspar on this site: 13 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Andesine) is marked.
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Feldspar materials | Live |
| Treatments recorded for this material | Filled / Fracture-filled (via parent material), Coated (via parent material), Diffusion-treated, Irradiated (via parent material) | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Andesine 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.