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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
Diopside
Also known asChrome diopside (conditional name) · Star diopside · Violan · Violane
A pyroxene-group mineral species whose basic name in Annex A.1 of GB/T 16552-2017 is “diopside”; calling it chrome diopside requires meeting colour and composition conditions. 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 Diopside 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 DiopsideHow far lab testing can go and whether a synthetic exists
- Caring for and wearing DiopsideCleaning, heat, chemicals and light, as the cited sources give them; durability indicators and wearing advice
- Hardness, density and refractive index of DiopsideEach value with its source and check date
- Diopside 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 DiopsideWhere the name comes from
- Listing and disclosing DiopsideThe listing name to use; what must be disclosed before sale
- Standard clauses that define DiopsideWhich 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
Diopside, CaMgSi2O6, is a member of the pyroxene group and forms two solid-solution series—one with hedenbergite and one with johannsenite. Metamorphosed siliceous rocks rich in calcium and magnesium, of the pyroxene-hornfels or epidote-amphibolite facies, are its type setting; it is abundant in skarns and in Ca-Mg-rich gneisses and schists, and in certain peridotites and kimberlites, while being rarer in andesites and alkalic olivine basalts. Chromium-bearing diopside is green and is marketed as chrome diopside.
Scope: Covers the origin, composition and occurrence of diopside as a pyroxene-group mineral species, including the variety boundaries of chrome diopside; does not address synthetic materials.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Where it forms
Siliceous, calcium- and magnesium-rich rocks that were metamorphosed under pyroxene-hornfels or epidote-amphibolite facies conditions
Sources Handbook of Mineralogy
Skarns, together with Ca-Mg-rich schists and gneisses
Sources Handbook of Mineralogy
Some kimberlites and peridotites; less common in alkalic olivine basalts and andesites
Sources Handbook of Mineralogy
How it forms, step by step
Ca-Mg-rich siliceous protoliths react under contact or regional metamorphism, supplying Ca, Mg and Si.
Sources Handbook of Mineralogy
Under pyroxene-hornfels or epidote-amphibolite facies conditions, diopside crystallizes and grows.
Sources Handbook of Mineralogy
In skarns, diopside coexists with calcite, forsterite, wollastonite, grossular, vesuvianite and others.
Sources Handbook of Mineralogy
When chromium is present, diopside may be green (chrome diopside).
Sources CIBJO Gemstone Book 2022
Link to appearance
Diopside may be colorless, white, yellow, pale to dark green, or black, with a vitreous or dull luster; darker varieties such as chrome diopside are green.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Timescale
The sources state no timescale for diopside formation.
Sources Handbook of Mineralogy · CIBJO Gemstone Book 2022
Supporting findings
Diopside characterises metamorphosed siliceous rocks rich in calcium and magnesium that belong to the pyroxene-hornfels or epidote-amphibolite facies, and it is abundant in skarns and in Ca-Mg-rich gneisses and schists, as well as in certain peridotites and kimberlites.
Evidence grade BScope: Describes diopside's occurrence environment; not the sole origin of any one locality.
Sources Handbook of Mineralogy
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
Asia
- Inagli, Aldan, Sakha (Yakutia), RussiaChrome diopside; gem locality of the 1990s
Sources Gems & Gemology Winter 2000 · Handbook of Mineralogy
- Kunlun Mountains, Xinjiang, ChinaDescribed as large gemmy crystals
Sources Handbook of Mineralogy
Europe
- Ala Valley, Lanzo Valleys, Piedmont, ItalyOne of the co-type localities
Sources Mindat: Diopside
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
Chrome diopside is the green, chromium-bearing variety of diopside; its green color is due to chromium, and it normally requires no treatment.
Evidence grade AScope: Describes chrome diopside's color cause and variety status; not generalized to other-colored diopside.
Sources CIBJO Gemstone Book 2022
Diopside's cat's-eye, and the four-rayed star of 'star diopside', is produced by oriented needle-like or channel inclusions inside the stone: mutually parallel inclusions scatter and reflect light that a cabochon collects into a bright band lying across the inclusion length, and when two sets of parallel inclusions intersect, the bands cross to give a four-rayed star. Diopside is monoclinic, and its lower symmetry limits the number of needle orientations, so four-rayed stars are common rather than six-rayed ones.
Evidence grade AScope: Applies to diopside varieties with parallel inclusions that show chatoyancy or asterism; identifying the specific inclusion type needs separate testing, and the mechanism does not establish origin, naturalness, or treatment.
Where the name comes from
The English name diopside comes from two Greek words, “double” and “appearance,” apparently alluding to the two possible orientations of the prism zone.
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
Diopside has the formula CaMgSi2O6, belongs to the pyroxene group, and forms two solid-solution series — with hedenbergite and with johannsenite.
Evidence grade BScope: Describes diopside composition and solid-solution series; it does not infer end-member ratios of any sample.
Sources Handbook of Mineralogy
Star diopside (with an asterism effect) and the purple variety violane are varieties of diopside, which itself is an independent mineral species.
Evidence grade AScope: Defines diopside's variety-to-species relationship; it does not treat variety names as independent species.
Sources CIBJO Gemstone Book 2022
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The sources state no absolute geological timescale for diopside formation.
- The mechanism of the cat's-eye/asterism effect is not described in the available sources; only the variety's identity is recorded.
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
- Diopside
GB/T 16552—2017 Table A.1 “Diopside” · IMA Mineral List 2026-07 “Diopside”
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
Diopside is Diopside; use "Diopside" for listings, and disclose any known treatments.
Evidence
- GB/T · Table A.1, row 透辉石 (Diopside)
What this means for you
Before buying, check the recommended listing name "Diopside" 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
Diopside — 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, Diopside, p.50; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Diopside — 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
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Diopside, p.50; §6.2 b (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Diopside — care (special care): chrome diopside: special care (SC); avoid sudden temperature change and harsh chemicals.
AGTA Gemstone Information Manual, 17th ed.
- Treatment state
- untreated
Source & check 2026-09-26
- Source
- AGTA Gemstone Information Manual, 17th edition (August 2026) (AGTA): p.X, Gemstone Information Chart, Diopside (Chrome) N, CARE REQUIRED / SPECIAL ADVICE (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.
Common care questions and matching entries
CleaningWhatever the treatment state, the CIBJO Gemstone Book 2022 states that Diopside must not be cleaned ultrasonically, and that it fractures easily and should be worn with care. UntreatedFor untreated chrome diopside, the AGTA Gemstone Information Manual, 17th edition, states that it needs special care (marked SC) and should be kept away from sudden temperature changes and harsh chemicals.
This table scrolls sideways on narrow screens.
| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | care (cleaning) |
| Wearing limits (knocks, settings) | cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care |
Care entries by treatment state
The same entries grouped by the treatment state each applies to; each links to its full wording and source. Letters are CIBJO special-care codes, explained on the gemstone care page.
any treatment state
- care (cleaning) §6.2 j
- cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care §6.2 b
untreated
Durability and wearing
Toughness
Brittle
Fracture
Uneven to conchoidal
Sources Handbook of Mineralogy
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Diopside, the name register records "Chrome diopside", "Star diopside", "Violan" and "Violane", for which no restriction on use as a name is recorded (CIBJO Gemmological Laboratories Book 2024 §7.2.1.228 “Star diopside”; CIBJO Gemstone Book 2022 Annex 8 “Star Diopside”; CIBJO Gemstone Book 2022 Annex 8 “Violan”; CIBJO Gemmological Laboratories Book 2024 §7.2.1.260 “Violane”; CIBJO Gemstone Book 2022 Annex 8 “Violane”); 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 Chinese formal name of Diopside comes from GB/T 16552—2017 Table A.1, and the suggested listing name is Diopside. Trade and mineralogical namesThe mineralogical name is Diopside; the trade name or synonym Chrome diopside refers only to the green chromium-bearing variety, and the name Chrome diopside, in English or Chinese, may be used only when the colour and composition conditions are met. Names in four languagesThe four-language names are the Simplified and Traditional Chinese names, English Diopside and the Japanese names, with the GSJ (Japan) formal name written in kanji. Institution usageFor authority wording, the CIBJO Gemmological Laboratories Book 2024 records Diopside; the FTC text on file has no wording for Diopside (checked); GIA and Gem-A are unchecked. Bodies without a recorded wording show the entry's own English name, which does not represent their position. The entry also records narrower names (varieties or subtypes) such as Star diopside, Violan, Violane and the Chinese name for chrome diopside.
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 (5) | ||||
| Chrome diopsideEnglish | narrower name (variety or subtype) | matched only once the condition is confirmed | no restriction recorded | editorial ruling (no clause cited) |
| Star diopsideEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.228 “Star diopside”; CIBJO Gemstone Book 2022 Annex 8 “Star Diopside” |
| ViolanEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Violan” |
| ViolaneEnglish | narrower name (variety or subtype) | matched automatically | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.260 “Violane”; CIBJO Gemstone Book 2022 Annex 8 “Violane” |
| 铬透辉石Simplified Chinese | narrower name (variety or subtype) | matched automatically | no restriction recorded | GB/T 16553—2017 5.1.25 |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- 透輝石
- Chinese formal name
- 透辉石 (GB/T 16552—2017 Table A.1)
- Mineralogical name
- Diopside
- Trade names and synonyms
- Chrome diopside (narrower name (variety or subtype); conditional name) · Star diopside (narrower name (variety or subtype)) · Violane (narrower name (variety or subtype)) · Violan (narrower name (variety or subtype))
Four-language names
- 简体中文
- 透辉石
- 繁體中文
- 透輝石
- English
- Diopside
- 日本語
- ダイオプサイド／透輝石
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
Among the material facts for Diopside, the chemical composition is CaMgSi2O6, possibly with Cr, Fe, V, Mn and other elements, and the crystal system is monoclinic. Registered from pyroxene (the whole mineral group): crystalline; Mohs hardness 5–6; two directions of perfect cleavage (usually not visible in aggregates); anisotropic, biaxial, positive; untreated, lustre is vitreous per pyroxene (the whole mineral group). Diopside has a density of 3.22–3.4 g/cm³; the cited clause gives 3.29 with a permitted tolerance of (+0.11, −0.07), and the range is derived from this. Refractive index 1.665–1.73; the cited clause gives 1.675–1.701 with a permitted tolerance of (+0.029, −0.010), the range is derived from this, and 1.68 is commonly seen with the spot method. Birefringence 0.024–0.03. Untreated pleochroism is light to dark green. The UV-visible spectrum has an absorption peak at 505 nm, and chrome diopside has absorption peaks at 635 nm, 655 nm and 670 nm and a double absorption peak at 690 nm.
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 pyroxene (the whole mineral group), so they are not repeated on the Diopside page; see the material facts on the Pyroxene entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Diopside (how to read class-level values).
Definition
Diopside — nomenclature status: IMA status A: approved (accepted by the IMA after it was set up in 1958).
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Diopside — composition (chemistry): diopside: CaMgSi2O6; may contain Cr, Fe, V, Mn and other elements.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Chemical composition · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — composition (phase): diopside
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Structure
Diopside — structure (overall): crystalline
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — structure (crystal system): monoclinic
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Crystal system · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — structure (crystal system): monoclinic for diopside, augite and spodumene; orthorhombic for enstatite.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — structure (crystal habit): usually prismatic, sometimes forming flaky, radiating or fibrous aggregates; augite can form platy crystals.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Diopside — Mohs hardness: 5–6
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
- pyroxene (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — cleavage: cleaves perfectly in two directions; aggregates normally show no cleavage.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Physical properties
Diopside — density: 3.22–3.4 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 3.29, with a stated tolerance of +0.11 / -0.07. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Density · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — density: 3.1–3.52 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Diopside — optic character: biaxial, optically positive (anisotropic)
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — refractive index: 1.665–1.73
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- Qualification
The clause we cite gives 1.675–1.701, with a stated tolerance of +0.029 / -0.010. The range shown here is worked out from that. The clause also gives 1.68 as the value commonly read by the spot method.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Refractive index · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — refractive index: 1.66–1.772
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — birefringence: 0.024–0.03
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Birefringence · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — birefringence: 0.008–0.033
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
- General note
- the clause has finer ranges
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — transparency: transparent.
CIBJO Gemmological Laboratories Book 2024
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Diopside — pleochroism: light to dark green
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Pleochroism · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — pleochroism: trichroism, weak to strong. Diopside shows light to dark green; enstatite shows brownish yellow and yellow, or green and yellow-green; augite shows light green, light brown and green-yellow. Pink-red to blue-purple-red spodumene is moderate to strong, showing pink-red and light purple-red; colorless and green spodumene is moderate, showing blue-green and yellow-green.
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Diopside — fluorescence (overall): green diopside: long wave green; short wave none.
GB/T 16553—2017
UV fluorescencegreengreen diopsideDots are illustrative colours built from the colour names, not measured values
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Fluorescence (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — spectrum (UV-visible): 505 nm absorption peak; chrome diopside: 635 nm absorption peak; 655 nm absorption peak; 670 nm absorption peak; 690 nm double absorption peak.
GB/T 16553—2017
- Does this standard apply
- applies to this entry
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 UV-visible spectrum (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
Diopside — optical effect (chatoyancy): seen
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
optical effect (asterism)2 sources compared
Diopside — optical effect (asterism): asterism.
CIBJO Gemmological Laboratories Book 2024
- Qualification
The cited source states that this effect may occur.
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Diopside — optical effect (asterism): seen; a four-pointed star
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
body colour2 sources compared
Diopside — body colour: Medium to dark, vivid green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Aventurine Quartz, Emerald, Spodumene and other entries also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Diopside — body colour: blue-green to yellow-green, brown, black, violet, white to colourless.
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, Turquoise, Nephrite and other variety clauses also name green or a greenish colour.
- General note
- colour alone is not identity
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 Colour · Diopside (locator checked 2026-09-28)
- Fact checked on
- 2026-09-26
How the sources relate
- CIBJO Gemmological Laboratories Book 2024 and GB/T 16553—2017
The two entries cover different ranges: the entry in the CIBJO Gemmological Laboratories Book refers to chrome diopside only (medium to dark, vivid green), while GB/T 16553—2017 lists blue-green to yellow-green, brown, black, violet and white to colourless for diopside. They agree on green.
- CIBJO definitions
- chatoyancy, asterism
Quality factors
Diopside — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- pyroxene (the whole mineral group)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.1.25 (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): 1.716 / 3.31; Closest values: 1Vesuvianite / Idocrase 1.711 / 3.38, 2Hydrogrossular 1.7 / 3.35, 3Tanzanite 1.696 / 3.28, 4Epidote 1.737 / 3.38, 5Axinite 1.683 / 3.31
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
According to the CIBJO Gemstone Book 2022, there is no synthetic Diopside on the market. In its testing-method rules, the CIBJO Gemmological Laboratories Book 2024 notes for diopside that its special optical effects are the cat's-eye effect and the star effect.
The tests the CIBJO laboratory protocol requires for this material, and what each method means, are in the protocol table on the laboratory testing page: §6.1.25.
How far testing can go
Diopside — synthetic counterpart on the market: No synthetic counterpart of this material is commercially available
CIBJO Gemstone Book 2022
- Treatment state
- any treatment state
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Diopside — notes on test methods in the CIBJO laboratory protocol:
| Test method | What the protocol notes for it |
|---|---|
| Phenomena: | Cat’s-eye, star |
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- any treatment state
Source & check 2026-09-26
- Source
- 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.
Clause-level definitions
CIBJO Gemmological Laboratories Book 2024 gives clause-level definitions for Diopside under Chrome diopside, Diopside, Star diopside and Violane: Chrome diopside is medium to dark, vivid green and transparent; Diopside is the mineral species diopside, IMA status A, with the CIBJO wording quoted in full under Clause-level definitions on this page; Star diopside is dark green to black diopside with asterism; Violane is a violetish blue, translucent to opaque, manganese-rich variety of diopside. On cross-checking, Chrome diopside, Diopside, Star diopside and Violane are all defined directly by CIBJO; no identically named English entry for Chrome diopside, Star diopside or Violane was found in this edition of the GB/T annex, while Diopside also appears in the GB/T annex. Diopside is also in the IMA Mineral List entry, written as Diopside, formula CaMgSi2O6, IMA status A, 1988 s.p., cross-checked against the RRUFF/IMA master mineral list (public domain data).
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Chrome diopside | 7.2.1.52 | Medium to dark, vivid green, transparent | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Diopside | 7.2.1.74 | Green, yellow, colourless, brown, black, blue to violet, transparent, translucent and opaque. May show asterism (‘black star’) | Defined directly by CIBJO; also present in the GB/T annex. |
| Star diopside | 7.2.1.228 | Dark green to black diopside, with asterism | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Violane | 7.2.1.260 | Violet-blue, translucent, opaque, Manganese- rich variety of diopside | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Diopside | IMA Mineral List entry | Diopside CaMgSi2O6 A 1988 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.
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| 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 Diopside 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.