Bruneau Jasper Identification Guide
Identifying Bruneau jasper, a prized scenic Idaho jasper, by its egg-shaped orb patterns, earthy colors, hardness, and how it differs from similar jaspers.
Read the full Bruneau Jasper encyclopedia entry →
What Bruneau Jasper Looks Like
Bruneau jasper is a famous scenic ("picture") jasper from the Bruneau River canyon in southwestern Idaho. It is an opaque microcrystalline quartz known for landscape-like patterns: concentric orbs and egg shapes, swirls, and "canyon" scenes in earthy tones of brown, tan, cream, deep red, mahogany, and forest green, often with sky-blue or gray zones. Luster is waxy when rough, glassy when polished; it is fully opaque.
Crystal habit / form
No visible crystals—cryptocrystalline quartz. It occurs as a massive seam/nodule deposit. Broken surfaces show conchoidal fracture and no cleavage. The orbicular patterning (rounded eyes/orbs) is the signature texture that distinguishes premium Bruneau material.
Step-by-Step Field ID Checklist
- Look for orbs and scenes. Concentric egg-shaped orbs and landscape banding in earthy colors point to Bruneau.
- Confirm opacity. Even thin slices block light.
- Check luster—waxy/greasy raw, glassy polished.
- Test hardness. Scratches glass, resists a knife (Mohs ~6.5–7).
- Examine the break—smooth conchoidal, no flat cleavage.
- Acid test—no fizz.
Key Diagnostic Tests
- Mohs hardness: ~6.5–7. Scratches glass; a knife will not mark it.
- Streak: White (faint rusty smear possible from iron staining).
- Fracture: Conchoidal, no cleavage.
- Acid: Inert with dilute HCl.
- Density: ~2.6 g/cm³.
- Magnetism: None.
Common Look-Alikes and How to Tell Them Apart
- Owyhee / Biggs / Deschutes picture jaspers: Other Pacific Northwest scenic jaspers. They overlap in color and scenery; Bruneau is specifically prized for tight, well-defined egg-shaped orbs and rich mahogany-and-green canyon scenes. Locality and the distinctive orb pattern are the practical separators—physical tests are identical (all are jasper).
- Mookaite: Australian jasper in red/yellow/white; lacks Bruneau's orb-and-canyon scenery.
- Agate: Translucent and banded—backlight to separate from opaque jasper.
- Petrified wood: Shows wood grain rather than orbs.
- Dyed jasper: Overly vivid, uniform color can indicate dye; natural Bruneau tones are earthy and subtle.
Where It Is Found
Bruneau jasper comes almost exclusively from a deposit in the Bruneau Canyon area of Owyhee County, southwestern Idaho, USA, where silica filled cavities in volcanic (rhyolitic) host rock. The classic claim has historically been worked intermittently, making fine old material collectible. It is cut into cabochons, spheres, and ornamental pieces that showcase the scenic patterns.
Frequently asked questions
How can you tell if it's real Bruneau jasper?
Genuine Bruneau jasper is opaque jasper (Mohs ~6.5–7, scratches glass, conchoidal fracture, no acid reaction) showing its signature tightly defined egg-shaped orbs and mahogany, cream, red, and green canyon-like scenery. Provenance from the Bruneau Canyon area supports authenticity.
Where does Bruneau jasper come from?
Bruneau jasper is found in the Bruneau River canyon area of Owyhee County in southwestern Idaho, USA, where silica filled cavities in volcanic rock.
What makes Bruneau jasper special compared with other picture jaspers?
It is valued for its crisp, concentric egg-shaped orbs and richly colored canyon scenes in earthy browns, reds, and greens, which are more sharply defined than in many other scenic jaspers.
Is Bruneau jasper the same as Owyhee jasper?
They are different deposits from the same general region of the Pacific Northwest. Both are scenic jaspers and test identically, but Bruneau is known for orb patterns while Owyhee material often shows blue-toned scenic banding.