W002 / Idaho
Bruneau jasper
A locality-linked jasper · Bruneau River canyon
Cream-colored eyes in warm brown stone are the familiar Bruneau look. The name belongs to Idaho’s Bruneau canyon material—not to every jasper with little circles.
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Chris857 · CC BY-SA 3.0 · Photograph reproduced without cropping or colour changes.
The source identifies Bruneau, Idaho and the A. E. Seaman Mineral Museum display. Exact deposit and specimen chain of custody have not been independently verified.
What it is
Fine-grained silica-rich jasper associated with volcanic rocks in the Bruneau canyon area.
What to look for
Brown and cream curves, rounded eyes and bands are useful comparison features. A polished face shows pattern; an unpolished, dry face shows the condition more honestly.
At the cutting bench
Used for cabochons and polished display pieces. Plan around fractures before choosing the most striking eye. Do not judge cutting yield from a wet photo alone; ask for dry views, edge views and measured thickness.
Under the loupe
Use documented Bruneau examples for comparison, but do not certify origin from the eye pattern. Orbicular and picture jaspers from elsewhere can overlap in appearance. An estate acquired in Oregon may contain Idaho material.
Source & collecting access
UNKNOWN — current mine-by-mine production and access are not verified. An older BLM guide reports substantial depletion. That statement does not prove complete exhaustion, establish today’s claim ownership, or make collecting lawful.
Status checked September 2026The market notebook
Market data insufficient for a reliable range. Copper Canyon slab2107 asks US $25; its thickness is described as 1/4 inch, but the generic dimensions conflict. Separately, Heritage reports US $79 sold for a finished 148.22 ct cabochon on 16 October 2025. These are different product forms, not the ends of a slab-price range.
Market researched 30 September 2026Open the field notes
Names, labels & aliases
Bruneau Canyon jasper. “Bruneau” used on a sales label is a provenance claim, not a laboratory result.
How it formed
The university reference collection describes jasper filling spaces in welded volcanic ash deposits and rhyolitic rocks. This supports a volcanic setting; a detailed deposit-by-deposit formation model needs further primary research.
The collecting story
BLM’s boating guide places the first local jasper claims in the 1950s. Historic advertising is preserved in the university’s bibliography, including a correction of an Oregon attribution. The date a label was printed matters when reconstructing an old collection.
Reading an old-stock label
Older labelled stock may preserve evidence missing from a loose slab. Keep original labels, invoices and handwriting with the piece. A present-day scarcity claim does not prove that a seller’s stock is old.
What we know—and what we don’t
WELL SUPPORTED: Idaho regional attribution and historic trade name. UNKNOWN: current source status and unlabeled-piece provenance. A dealer’s Oregon-labelled slab was excluded from geographical and pricing comparisons.
C&C Reference Collection
No C&C reference specimen has been authenticated for this record yet. Acquired in Oregon is not the same as formed in Oregon. Preserve an estate’s original wording and mark any lost locality documentation.
Sources & Further Reading
- University of Nebraska–Lincoln · Agates Collection
Historical names and locality-labelled reference specimens. Older entries are not current access advice; some geological interpretations need updating.
- USGS · Bulletin 1720-B (1988)
Publication and report location verified. Full report retrieval incomplete; not used to declare current mine status.
- BLM · Owyhee, Bruneau & Jarbidge boating guide, printed p. 11
Historical claim/depletion statement. Not a current claim search or permission to collect.
- Copper Canyon · Bruneau slab2107
Observed asking price. Description thickness conflicts with generic dimensions; plan dimensions not accepted as reliable.
- Heritage · Bruneau cabochon, lot 78052, 16 October 2025
Auction reports sold for $79; 148.22 ct, 73.30 × 53.77 × 5.10 mm. Finished cabochon is not a rough/slab comparable.
- BLM · Rockhounding
General collecting framework; local restrictions, claims and ownership must still be checked.
- CDC/NIOSH · Safe Work Practices for Silica
Dust control guidance; wet methods are one control, not a guarantee of safe exposure.
Silica-bearing stone can release hazardous dust when cut or ground. Use appropriate dust controls; wet working alone is not a safety guarantee.