Morrisonite Jasper Identification Guide

What Morrisonite Jasper Looks Like

Morrisonite is a rare, highly prized "picture jasper" from a single deposit in eastern Oregon. It is an opaque silica rock (jasper/chalcedony) famous for painterly scenes and orbicular (egg-shaped) patterns in soft blues, greens, sea-greens, browns, tans, peach, and cream. The colors are typically muted and pastel, blending in landscape-like or bull's-eye designs that take a glassy polish.

• Color: blue-green, sea-green, brown, tan, peach, cream — soft, blended
• Patterns: orbs (eyes), scenic/landscape banding, swirls
• Luster: waxy raw; vitreous polished
• Transparency: opaque

Step-by-Step Field ID Checklist

1. Look for the patterns. Orbicular "egg" patterns and pastel scenic blending are the signature of Morrisonite.
2. Check hardness: Mohs ~7 — it scratches glass and resists a knife (it is silica).
3. Confirm opacity: fully opaque, with a waxy break — like other jaspers.
4. Note the palette: soft blues and greens with brown/peach distinguish it from hot-colored jaspers.
5. Consider provenance. True Morrisonite is rare and high-value; verify the source claim.

Key Diagnostic Tests

• Hardness: 6.5–7.
• Fracture: conchoidal to uneven; no cleavage.
• Luster: waxy on break, glassy polished.
• Specific gravity: ~2.6.
• Acid: inert (silica).

Common Look-Alikes and How to Tell Them Apart

• Owyhee jasper: from the nearby Owyhee region; also scenic but generally with different (often bluer or more muted earthy) tones. Morrisonite is distinguished by its orbicular patterns and specific pastel blue-greens, and by its single-mine provenance.
• Biggs jasper: an Oregon picture jasper dominated by tan/brown landscape banding, lacking Morrisonite's blue-green orbs.
• Bruneau jasper (Idaho): orbicular like Morrisonite but typically richer red-brown and cream; color palette differs.
• Ocean jasper: orbicular too, but from Madagascar with brighter green/red/white orbs and often a druzy interior.
• Imitations/other jaspers: test hardness (~7) and look for natural, gradational color zoning.

Where Morrisonite Jasper Is Found

Morrisonite comes from the Morrison Ranch deposit along the Owyhee River canyon area in Malheur County, eastern Oregon. The deposit is small, remote, and largely worked out, which is why genuine Morrisonite is scarce and sought after by collectors. Like other jaspers it formed from silica-rich solutions filling cavities and seams in volcanic host rock.

Forms, Treatments, and Field Notes

Morrisonite is firmly a collector and high-end lapidary material, so most pieces appear as carefully cut cabochons, polished slabs, and finished jewelry rather than rough. Because the deposit is essentially exhausted, prices are high and misattribution is common — generic Oregon picture jasper is sometimes sold under the Morrisonite name. The genuine article is known for its refined pastel blue-green orbicular and "porcelain" patterns and an exceptionally fine, glassy polish.

Authentication tips

Treat any piece skeptically without provenance, then apply physical checks: hardness ~7 (scratches glass), full opacity, and a waxy conchoidal fracture confirm it is a real silica jasper, while the distinctive soft blue-green orbs and scenic blending point specifically to Morrisonite. Compare suspect stones side by side with documented Owyhee, Biggs, and Bruneau jaspers, whose palettes differ, and favor sellers who can trace material to the Morrison Ranch source.