On this page
UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Rock / mineral aggregate · Natural identity; treatment status unknown
Ophicalcite
Also known asConnemara · Verd Antique
A rock in which Serpentine and marble are intermixed; it is neither pure Marble nor pure Serpentine, and the name is a petrological one. Also known as Verd-antique. 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 Ophicalcite forms and what gives its colourFormation setting, process and timescale, each finding graded and sourced
- How to identify OphicalciteHow far lab testing can go and whether a synthetic exists
- Treatments and enhancements of Ophicalcite1 registered treatments: status, stability, how common they are and identification leads
- Caring for and wearing OphicalciteCleaning, heat, chemicals and light, as the cited sources give them
- Hardness, density and refractive index of OphicalciteEach value with its source and check date
- Ophicalcite 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 OphicalciteThe listing name to use; what must be disclosed before sale
- Standard clauses that define OphicalciteWhich 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
Serpentine marble is a mixed rock/aggregate in which carbonate (mainly calcite, sometimes dolomite) is intergrown with serpentine-group minerals. Its carbonate component derives from limestone or marble: heating and squeezing of limestone recrystallizes the grains into marble; the magnesian component derives from the hydration (serpentinization) of ultramafic rocks. In places such as Val Malenco in the Alps, serpentine occurs intercalated with forsterite olivine-bearing marbles. The serpentine group includes lizardite, chrysotile and antigorite, polymorphs of the Mg-rich hydrous phyllosilicate with approximate formula Mg3Si2O5(OH)4, which transforms from lizardite/chrysotile to antigorite with increasing temperature. Because its structure and appearance resemble jadeite and nephrite, serpentine marble is often used as their imitation.
Scope: Applies to an overview of the diagenetic/metamorphic genesis and composition of ophicalcite (a mixed carbonate + serpentine rock); composition varies with locality and component proportions.
Sources G&G Spring 2016 · G&G Summer 2020 · USGS FAQ: limestone and marble
Where it forms
Settings where limestone/marble and ultramafic rocks meet and hydrate (regional or contact metamorphism), e.g. Val Malenco in the Alps, where serpentine is intercalated with olivine-bearing marbles.
Sources G&G Spring 2016
Crustal high-temperature conditions (regional metamorphism) in which carbonate grains recrystallize.
Sources USGS FAQ: limestone and marble
How it forms, step by step
Carbonate sediment (limestone) forms, the precursor of the marble component.
Sources USGS FAQ: limestone and marble
The limestone is heated and squeezed, and calcite grains recrystallize into marble.
Sources USGS FAQ: limestone and marble
Adjacent ultramafic rocks hydrate (serpentinization), forming serpentine-group minerals such as lizardite and chrysotile.
Sources G&G Spring 2016
With increasing metamorphic temperature, antigorite grows from lizardite/chrysotile, producing the final serpentine-marble assemblage.
Sources G&G Spring 2016
Link to appearance
Serpentine marble may show a yellow weathered skin and grainy texture resembling jadeite rough; its green colour can be applied by dyeing (removable with alcohol), and the carbonate component effervesces with dilute acid.
Sources G&G Summer 2020
Timescale
No absolute age for the metamorphic event is given, so no timescale is stated.
Sources G&G Spring 2016
Related base materials
- Serpentine-group minerals (antigorite, lizardite, chrysotile): Serpentine component of the rock
- Calcite: Carbonate (marble) component of the rock
Supporting findings
Marble is produced when limestone—a sedimentary rock—is subjected to heat and compression, causing its calcite grains to recrystallize. Limestone itself originates as shells, sand and mud that settle, in oceans and lakes, and harden over time into rock.
Evidence grade AScope: Describes the carbonate component's genesis; not the serpentine component.
Sources USGS FAQ: limestone and marble
Serpentinization—the making of serpentine minerals—takes place when olivine-rich ultramafic rocks are hydrated at fairly low temperatures. As metamorphic grade rises, antigorite, the high-temperature phase, develops out of lizardite and chrysotile at temperatures exceeding roughly 320 C.
Evidence grade AScope: Describes the serpentine component's genesis and stability field; not the carbonate component.
Sources G&G Spring 2016
Other research findings
Serpentine marble is a mixed rock/aggregate of carbonate (mainly calcite) intergrown with serpentine-group minerals, its composition varying by locality and component ratio.
Evidence grade AScope: Defines it as a mixed rock; not a single mineral species.
Sources G&G Spring 2016 · G&G Summer 2020
The serpentine group comprises lizardite, chrysotile and antigorite; these are polymorphs of one Mg-rich hydrous phyllosilicate whose formula is approximately Mg3Si2O5(OH)4.
Evidence grade AScope: Applies to the serpentine component; the whole rock also contains carbonate.
Sources G&G Spring 2016
Serpentinized marble can be mistaken for jadeite rough; dilute acid (carbonate effervescence), hardness and infrared spectroscopy identify it as a carbonate rock.
Evidence grade AScope: States identification points relative to its use as an imitation; not a determination of a specific sample.
Sources G&G Summer 2020
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- Serpentine marble is a mixed rock whose composition varies by locality and ratio; only a general overview is given.
- No absolute age for its genesis is given in the cited sources.
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
- Ophicalcite
GB/T 16552—2017 5.1.1 b) · CIBJO Gemmological Laboratories Book 2024 §7.2.1.166 “Ophicalcite”
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
"Ophicalcite" is a market name rather than a mineral species name; before using it, verify: Laboratory identification required before the name is used.
Evidence
- GB/T · 5.1.1 b)
What this means for you
Before buying, check the recommended listing name "Ophicalcite" 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
- Ophicalcite
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
Ophicalcite — 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, Ophicalcite, p.66; §6.2 j (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ophicalcite — care (heat): can crack if it loses structural water, so keep it away from heat and drying environments; prone to damage from thermal shock; do not expose it to extreme temperature changes.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code d, special-care code e
- Treatment state
- untreated
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ophicalcite, p.66; §6.2 d, e (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ophicalcite — care (chemicals): Some stones are porous. Do not allow contact with coloured fluids.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code c
- 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, Ophicalcite, p.66; §6.2 c (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ophicalcite — care (chemicals): particularly susceptible to attack by acids, so keep it away from acids; treatments with dye, oil, resin, wax or plastic are not permanent; keep it away from all solvents (including dish-washing liquids), chemicals and heat.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code h, special-care code k
- Treatment state
- treated
- Only after these treatments
- impregnation
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ophicalcite, p.66; §6.2 h, k (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ophicalcite — 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, Ophicalcite, p.66; §6.2 b (locator checked 2026-09-25)
- Fact checked on
- 2026-09-25
Ophicalcite — care (wear): Some stones are prone to scratching due to low hardness. Wear them with care.
CIBJO Gemstone Book 2022
CIBJO Gemstone Book §6.2:special-care code a
- Treatment state
- treated
- Only after these treatments
- impregnation
Source & check 2026-09-25
- Source
- CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022) (CIBJO): §8 Annex C, Ophicalcite, p.66; §6.2 a (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
The care conclusions for Ophicalcite come from the CIBJO Blue Book — Official Gemstone Book (Coloured Stone Commission 2022). CleaningOn cleaning, regardless of treatment status, it should not be cleaned ultrasonically. HeatOn heat, when untreated it may crack on losing water, so keep it away from heat and dry conditions; it is also sensitive to sudden temperature changes. ChemicalsOn chemicals, regardless of treatment status, it is porous, so keep it away from coloured liquids; for treated stones, in the case of impregnation only, it is particularly sensitive to acid and must be kept away from acids, and dyeing, oiling, resin impregnation, waxing and plastic impregnation all have poor durability, so keep it away from solvents (including detergent), chemicals and heat. WearOn wear, regardless of treatment status, it is prone to breaking, so wear it with care; for treated stones, in the case of impregnation only, it is soft and scratches easily, so wear it with care.
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| Question | Matching entries |
|---|---|
| Can it go in an ultrasonic or steam cleaner? | care (cleaning) |
| Heat and thermal shock | can crack if it loses structural water, so keep it away from heat and drying environments; prone to damage from thermal shock; do not expose it to extreme temperature changes |
| Contact with acids, alkalis and household chemicals | care (chemicals); particularly susceptible to attack by acids, so keep it away from acids; treatments with dye, oil, resin, wax or plastic are not permanent; keep it away from all solvents (including dish-washing liquids), chemicals and heat |
| Wearing limits (knocks, settings) | cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care; care (wear) |
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
- care (chemicals) §6.2 c
- cleaves or fractures easily or is brittle (e.g. rubbed facet edges); wear with care §6.2 b
untreated
treated (Only after these treatments: impregnation)
Treatments and identification leads
Registered treatmentsThe registered treatment for Ophicalcite is impregnation. Stability and frequencyImpregnation has the status treated, an effect stability of unstable and a prevalence of occasional. Values not givenWhere the impregnation record shows “—”, the cited source gives no value, which does not mean “none”. SyntheticsNo synthetic counterpart of Ophicalcite is on the market.
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| Treatment | Market frequency (CIBJO) | Stability (CIBJO) | GB/T 16552 category | JJA/AGL listing | Identification leads |
|---|---|---|---|---|---|
| impregnationStatus: treated | occasionally | unstable | — | — | — |
Where each treatment acts (schematics): Impregnated
“—” means the cited source gives no value for that item, not “none”. Source: CIBJO Gemstone Book 2022
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 Ophicalcite, the name register records "Connemara", "Verd Antique" and "Verd-antique", for which no restriction on use as a name is recorded (CIBJO Gemstone Book 2022 Annex 8 “Connemara”; CIBJO Gemstone Book 2022 Annex 8 “Verd Antique”; CIBJO Gemmological Laboratories Book 2024 §7.2.1.256 “Verd-antique”).
Standard and listing namesOphicalcite is not listed in Annex A of GB/T 16552—2017, but that standard allows Ophicalcite to be named directly; the suggested listing name is serpentine marble (Ophicalcite). Institution usageThe CIBJO Gemmological Laboratories Book 2024 has Ophicalcite on record; the FTC text on file has no wording for Ophicalcite (checked); GIA and Gem-A are unchecked. Japanese namesThe GSJ (Japan) wording for Ophicalcite's own Japanese name is not yet verified by this site. Names in four languagesThe four-language names cover Simplified Chinese, Traditional Chinese, English (Ophicalcite) and Japanese. Trade and mineralogical namesMarket names include Connemara, Verd Antique and Verd-antique; the mineralogical name is a mixed serpentine-marble rock.
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 (3) | ||||
| ConnemaraEnglish | market name | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Connemara” |
| Verd AntiqueEnglish | market name | matched automatically | no restriction recorded | CIBJO Gemstone Book 2022 Annex 8 “Verd Antique” |
| Verd-antiqueEnglish | market name | matched automatically | no restriction recorded | CIBJO Gemmological Laboratories Book 2024 §7.2.1.256 “Verd-antique”; CIBJO Gemstone Book 2022 Annex 8 “Verd Antique” |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- オフィカルサイト／蛇紋大理石 (not yet checked for this body — the entry's own Japanese name is shown)
- Mineral / material name (not in GB/T 16552 Annex A; usable directly)
- 蛇纹石大理岩 (GB/T 16552—2017 §5.1.1 b))
- Mineralogical name
- Serpentine-marble mixed rock
- Trade names and synonyms
- Connemara (market name) · Verd-antique (market name)
Four-language names
- 简体中文
- 蛇纹石大理岩
- 繁體中文
- 蛇紋石大理岩
- English
- Ophicalcite
- 日本語
- オフィカルサイト／蛇紋大理石
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Rocks and polymineral aggregates
- Identity tier
- Rock / mineral aggregate
- Mineral chemical class
- Mixed / composition-dependent
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The chemical composition, fluorescence, UV-visible spectrum, infrared spectrum and magnification of Ophicalcite are written in the cited clause for marble (the whole class); see the Marble entry. The material facts take the values for marble (the whole class): structure a crystalline aggregate, usually granular or fibrous; Mohs hardness 3; cleavage usually not seen on an aggregate; effervesces with a drop of hydrochloric acid when untreated; optic character anisotropic aggregate; refractive index 1.486–1.658; density 2.65–2.75 g/cm³, derived from the clause value 2.70 with tolerance ±0.05; lustre vitreous to greasy when untreated. The stability of the impregnation effect for treated material is “not stable”, which describes whether the impregnation treatment is stable, not whether Ophicalcite itself is durable.
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 marble (the whole class), so they are not repeated on the Ophicalcite page; see the material facts on the Marble entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Ophicalcite (how to read class-level values).
Structure
Ophicalcite — structure (overall): crystalline aggregate, usually granular or fibrous
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Ophicalcite — Mohs hardness: 3
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
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — cleavage: generally not seen on an aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — stability: effervesces on contact with hydrochloric acid
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
For Ophicalcite, the stability of impregnation is “unstable”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
- Qualification
This says how well the treatment holds up, not how durable Ophicalcite itself is.
- General note
- no durability verdict here
Source & check 2026-09-25
- Source
- Fact checked on
- 2026-09-25
Physical properties
Ophicalcite — density: 2.65–2.75 g/cm³
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
- Qualification
The clause we cite gives 2.70, with a stated tolerance of ±0.05. The range shown here is worked out from that.
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Ophicalcite — optic character: anisotropic material
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — refractive index: 1.486–1.658
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — birefringence: not measurable on an aggregate
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — pleochroism: not measurable on an aggregate
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Ophicalcite — body colour: Brown to grey-green.
CIBJO Gemmological Laboratories Book 2024
- Treatment state
- untreated
- Qualification
In chapter 7 of the CIBJO Gemmological Laboratories Book, the colour descriptions of Talc, Black Opal, Carbonado and other entries also name brown or a brownish colour.
- General note
- colour alone is not identity
Source & check 2026-09-22
- Source
- Fact checked on
- 2026-09-22
Quality factors
Ophicalcite — quality factor (lustre): vitreous to greasy
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- marble (the whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.18 (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): 1.572 / 2.7; Closest values: 1Shoushan Stone 1.56 / 2.7, 2Scapolite 1.558 / 2.67, 3Qingtian Stone 1.565 / 2.77, 4Aquamarine 1.58 / 2.79, 5Iolite 1.563 / 2.61
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
No synthetic counterpart of Ophicalcite is commercially available, in any treatment state. For Ophicalcite in trade, impregnation is reported occasionally, with treatment state treated for impregnation.
How far testing can go
Ophicalcite — 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
For Ophicalcite in trade, the reported frequency of impregnation is “occasionally”.
CIBJO Gemstone Book 2022
- Treatment state
- treated
- Treatment
- impregnation
Source & check 2026-09-25
- Source
- 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.
Clause-level definitions
Ophicalcite has the entry names Ophicalcite and Verd-antique registered in the clause-level definitions of the CIBJO Gemmological Laboratories Book 2024. The definition of Ophicalcite is registered as a rock, with the CIBJO wording quoted in full under Clause-level definitions on this page; Verd-antique is defined as mottled and/or veined dark green serpentine. For both Ophicalcite and Verd-antique the cross-check result is defined directly by CIBJO, and the same English name was not found directly in the GB/T annex of this edition.
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| Term | Clause | Definition | Cross-check |
|---|---|---|---|
| Ophicalcite | 7.2.1.166 | Brown to grey-green recrystallised impure limestone composed of calcite and serpentine; may be highly veined and brecciated | Defined directly by CIBJO; no identically named English entry was found in this edition of the GB/T annex. |
| Verd-antique | 7.2.1.256 | Mottled and/or veined dark green serpentine | 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.
- 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 | Rocks and polymineral aggregates | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Ophicalcite 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.