Queensland, Australia; the cover caption does not state a specific field.
Source locator · Gems & Gemology, Spring 1993, cover caption.
Source IDs · BOU006-SRC-003
Documented specimen record · BOU006
GIA 1993 cover · large Queensland boulder opal
A measured Queensland boulder-opal gem identified in the Spring 1993 Gems & Gemology cover caption, with ironstone matrix backing and a documented collection attribution.
Diagram · not specimen media · source image remains external
bou:specimen:gia-1993-cover-large-gem
Evidence record
- Source / collection
- George Brooks collection, Santa Barbara, California (as captioned by GIA).
- Provenance
- Queensland, Australia; the cover caption does not state a specific field. Confidence: documented.
- Host material
- ironstone matrix backing
- Opal component
- precious boulder opal on Queensland ironstone backing
- State
- finished
- Dimensions
- 47.05 × 37.65 × 8.36 mm
- Treatment / synthetic
- not stated by source; not inferred
- Pattern descriptor
- No named pattern assigned by the source; BOU does not add one.
Media rights
Authentic source image kept at the source.
The record is real; the diagram above is not the specimen. BOU006 does not reproduce the source photograph because reusable image rights were not independently established for ICU.
Rights status: external_reference_only_not_reproduced. Photo © Harold & Erica Van Pelt; Gems & Gemology / GIA cover caption.
Interpretation boundary
What stays unknown stays unknown.
This route does not infer treatment, mine identity, rarity, price or authenticity from appearance. A documented field relationship is linked only when the cited record supports it.
Evidence ledger
What is documented, contextual, observed and unresolved.
The ledger is intentionally fail-closed: a missing fact stays missing.
Use field/geology only within the documented link.
- Queensland-wide context only. No field is assigned because the specimen source does not state one.
Description stays descriptive.
- The source caption records a finished Queensland boulder-opal gem with ironstone matrix backing and exact measurements.
ICU visual classification status · not performed.
Unknowns are part of the record.
- Treatment status is not established by the cited source record.
- Natural versus laboratory-grown status is not independently determined by ICU.
- Monetary value, rarity grade and investment quality are outside this record.
- Specific Queensland field or mine provenance is unresolved.
When natural/laboratory-grown or treatment determination matters, use qualified gemological examination/testing. That still does not create automatic geographic origin or valuation.
ICU / CONNECTED DISCOVERY
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