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UnderstandWhat it is, what people ask, how far this page goes
Natural inorganic gem materials · Natural glass · Natural identity; treatment status unknown
Silver Sheen Obsidian
A trade optical name for obsidian showing a silvery sheen; it is a commercial description of the sheen, not a separate mineral species. 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 Silver Sheen Obsidian 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 Silver Sheen ObsidianHow far lab testing can go
- Hardness and refractive index of Silver Sheen ObsidianEach value with its source and check date
- Silver Sheen Obsidian in English, Chinese and Japanese; national standard namesNames in four languages, the GB/T standard name and the suggested listing name; and: Has any of GIA, FTC, CIBJO or Gem-A put a name for it on record here?
- Listing and disclosing Silver Sheen ObsidianThe listing name to use; what must be disclosed before sale
What we cannot conclude
- Whether one particular bead is natural, treated or synthetic — only a laboratory report can settle that.
- Geographic origin, unless an origin report accompanies the item.
- Price, rarity or investment value: this wiki covers naming and disclosure only.
Material research: formation, causes and history
What authoritative sources say about how this material forms, what causes its colour and optical effects, where its name comes from and how people have used it. Each statement carries an evidence grade and its sources; it describes the material in general, not any specific piece.
How it forms
Silver sheen obsidian is obsidian with a silvery grey sheen; its parent material is obsidian, a natural volcanic glass formed when silica-rich magma cools too fast to crystallize, occurring only in volcanic regions. The silver sheen arises from reflection off internal aligned inclusions (sometimes qualifying as aventurescence); studies remain limited.
Scope: Covers an overview of the formation of silver sheen obsidian; formation content follows that of the parent material obsidian, and the silver sheen mechanism is covered in the optical effects entry.
Sources NPS Hopewell Culture · NPS Obsidian Cliff · CIBJO Gemstone Book 2022 +1
Where it forms
Volcanic regions where silica-rich (rhyolitic/dacitic) magma cools rapidly.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
The parent obsidian is a glassy natural glass, black but also brown, tan, or green.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
How it forms, step by step
Silica-rich magma rises to the surface and cools rapidly.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
Cooling is too fast for atoms to arrange as crystals, producing amorphous volcanic glass.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
During solidification, aligned micro-inclusions/thin layers are preserved inside, giving the sheen/iridescent appearance.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
Link to appearance
An appearance-based name ('sheen') describes an optical effect and cannot alone establish identity, naturalness, treatment, or origin.
Sources CIBJO Gemstone Book 2022 · G&G Summer 2025
Timescale
The sources in this record give no absolute age or growth duration for this variety.
Sources NPS Hopewell Culture · NPS Obsidian Cliff
Related base materials
- obsidian: Obsidian is the parent material of this name; this name is an occurrence/optical variety name, not a separate material
Supporting findings
Obsidian is a natural volcanic glass (a glassy igneous rock) formed when silica-rich magma cools so rapidly that it does not crystallize, so it occurs only where there is volcanic activity.
Evidence grade AScope: Applies to the natural origin of obsidian (the parent material); it states rapid cooling, not a specific eruption age.
Sources NPS Obsidian Cliff · NPS Hopewell Culture
Recorded localities
Authoritative sources list the localities below; the list is not exhaustive.
North America
- MexicoOrigin of a GIA-illustrated sample; no mine named
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
The name refers to a variety of obsidian (parent material obsidian) whose appearance arises from reflection off internal aligned inclusions.
Evidence grade AScope: Describes the optical mechanism (reflection from aligned inclusions, sometimes aventurescence); does not claim it is an independent material.
Other research findings
In CIBJO gemmological nomenclature, obsidian is listed as a 'natural glass', an amorphous natural gem material rather than a mineral species.
Evidence grade AScope: Defines the material class of obsidian (natural glass); not a specific variety.
Sources CIBJO Gemstone Book 2022
Studies of these aligned-inclusion/thin-layer sheens in obsidian are still limited, and sheen obsidians from different localities differ markedly, so multiple mechanisms may be involved.
Evidence grade AScope: Acknowledges limited evidence; does not claim one mechanism explains all golden/silver sheen obsidian.
Limits of this research
- Research status: Formation, occurrence or other material-specific findings found in authoritative sources
- The sources give no quantitative mechanism for the silver sheen and explicitly note the limited research.
- Obsidian is a natural glass, not a mineral species; the variety name describes appearance only and is not a determinable material.
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
- Silver Sheen Obsidian
GB/T 16552—2017 5.1.1 c), 5.3.4
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
"Silver Sheen Obsidian" is a market name rather than a mineral species name; before using it, verify: Industry-wide term that does not denote a single species.
What this means for you
Before buying, check the recommended listing name "Silver Sheen Obsidian" and any disclosed treatments on this page, and ask the seller for a grading report if in doubt.
Known uncertainty
- This entry's exact material identity is not fully settled.
- See “Disclosure and cautions” above
- Last reviewed
- 2026-09-01
Trade-name ruling
- Industry-wide term that does not denote a single species.
- Suggested listing name
- Silver Sheen Obsidian
VerifyNames, standards, technical facts, clauses and sources
Names
Besides Silver Sheen Obsidian, the name register records "Silver sheen obsidian", for which no restriction on use as a name is recorded.
Standard and listing namesThe national-standard name corresponding to Silver Sheen Obsidian is natural glass (GB/T 16552—2017 Table A.2), and the name itself is not listed in the original; the suggested listing name is Silver Sheen Obsidian. Trade and mineralogical namesThe mineralogical name is paraphrased as obsidian showing a silvery sheen, and the trade name or synonym and the market name are both Silver sheen obsidian. Names in four languagesNames are given in Simplified Chinese, Traditional Chinese, English (Silver Sheen Obsidian) and Japanese. Institution usageOn authority wording, the FTC and CIBJO texts contain no wording for Silver Sheen Obsidian (checked), while GIA and Gem-A are unchecked; bodies without a recorded wording show the entry's own English name, which does not represent their position. Japanese namesOn GSJ (Japan), the entry has its own Japanese name, and the wording used by GSJ (Japan) for it is not yet verified by this site.
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 (1) | ||||
| Silver sheen obsidianEnglish | market name | matched automatically | no restriction recorded | editorial ruling (no clause cited) |
How each authority words this name: see Names › Authority wording.
- GSJ (Japan) formal name
- シルバーオブシディアン (not yet checked for this body — the entry's own Japanese name is shown)
- GB/T naming counterpart (this name is not in the standard)
- 天然玻璃 (GB/T 16552—2017 Table A.2)
- Mineralogical name
- Obsidian showing silver sheen
Four-language names
- 简体中文
- 银曜石
- 繁體中文
- 銀曜石
- English
- Silver Sheen Obsidian
- 日本語
- シルバーオブシディアン
See also: Misleading and prohibited trade names · Supplementary name index
Classification
- Origin
- Natural materials
- Material domain
- Natural inorganic gem materials
- Browsing family
- Natural glass
- Identity tier
- Natural glass
- Mineral chemical class
- Not applicable
- Construction or treatment status
- Natural identity; treatment status unknown
What it is and how it's identified
The material facts for Silver Sheen Obsidian are written by the cited GB/T 16553—2017 clause for natural glass as a whole class and are not measurements of Silver Sheen Obsidian alone. For natural glass as a whole, its overall structure is amorphous, cleavage is none, birefringence is none, and optical character is isotropic, often with anomalous extinction. For natural glass as a whole, its Mohs hardness is 5–6; this is the range for the whole class, which includes tektites and volcanic glass, not a measured value for Silver Sheen Obsidian. For natural glass as a whole, its refractive index is 1.48–1.51, derived from the cited clause's 1.490 with a tolerance of +0.020/−0.010. For natural glass as a whole, untreated Silver Sheen Obsidian shows no pleochroism and its lustre (quality factor) is vitreous. For whole-class features such as chemical composition, fluorescence, UV-visible spectrum, infrared spectrum and magnification, see the Natural Glass (material) entry.
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 natural glass (whole class), so they are not repeated on the Silver Sheen Obsidian page; see the material facts on the Natural Glass (material) entry.
Items below that name the class they cover give the cited clause’s value for that whole class, not a measurement of Silver Sheen Obsidian (how to read class-level values).
Structure
Silver Sheen Obsidian — structure (overall): amorphous (not crystalline)
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Durability
Silver Sheen Obsidian — 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
- natural glass (whole class)
- Qualification
This is the range for the whole class, not a measured value for this variety. The clause covers all natural glass (tektite and volcanic glass).
Source & check 2026-09-20
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-20)
- Fact checked on
- 2026-09-20
Silver Sheen Obsidian — cleavage: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Optical
Silver Sheen Obsidian — optic character: isotropic, usually with anomalous extinction
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silver Sheen Obsidian — refractive index: 1.48–1.51
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
- Qualification
The clause we cite gives 1.490, with a stated tolerance of +0.020 / -0.010. The range shown here is worked out from that.
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Silver Sheen Obsidian — birefringence: none
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-21
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-21)
- Fact checked on
- 2026-09-21
Silver Sheen Obsidian — pleochroism: none
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
Silver Sheen Obsidian — optical effect (chatoyancy): seen; rare
GB/T 16553—2017
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (locator checked 2026-09-26)
- Fact checked on
- 2026-09-26
- CIBJO definitions
- chatoyancy
Quality factors
Silver Sheen Obsidian — quality factor (lustre): vitreous
GB/T 16553—2017
- Treatment state
- untreated
- Does this standard apply
- applies to this entry
- What this covers
- natural glass (whole class)
Source & check 2026-09-26
- Source
- GB/T 16553—2017 Gems — Testing (GB/T): §5.2.29 (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.
Testing and market
The CIBJO laboratory protocol covers Silver Sheen Obsidian under “Obsidian” (§6.1.55): see identification on the Obsidian entry; the required tests are listed on the CIBJO laboratory protocol table for Obsidian.
How far testing can go
Each row's “Source & check” expands to the full source; the date beside it is the fact check date.
Evidence and sources
Authority basis and clause sources
Sources
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 Natural Glass (material) on this site: 7 entries listed by this site's parent-entry links; synthetic, treated and similar entries carry their recorded state after the name; this page (Silver Sheen Obsidian) is marked.
- Natural Glass (material)
Sub-entries (6)
- Golden Sheen Obsidian
- Obsidian
- Rainbow Obsidian
- Silver Sheen Obsidian
- Snowflake Obsidian
- Tektite / Moldavite
This table scrolls sideways on narrow screens.
| Page | Content | Status |
|---|---|---|
| Browsing family | Natural glass | Live |
| Related articles | To be added (placeholder) | Planned |
Who maintains this page
The material facts in the Silver Sheen Obsidian entry are maintained by the LumaLark wiki and matched one by one to the standard clauses or institutional sources they cite: every fact carries its source (with a clause or page locator) and a check date, so it can be traced back to the original. The entry exists so that buyers and sellers can check naming, disclosure and material facts item by item.