Owyhee Jasper is a highly sought-after orbicular variety of silicified rhyolite known for its distinct pastel blue, brown, and cream landscapes. It typically exhibits flow banding or sphere-like patterns when polished, making it a favorite for lapidary artists. It is found exclusively in the Owyhee Mountains region of Idaho and Oregon.
Spotting owyhee jasper in the field
Field marks- 1
Soft blue-grey and cream layering, gentler in contrast than Biggs
- 2
Frequently shows a hazy, atmospheric quality rather than sharp lines
- 3
Opaque, dense, no translucent edge
The Owyhee country straddling the Oregon, Idaho and Nevada corner is high, dry, remote and hard on vehicles, and it produces some of the best jasper and plume agate in North America. Material comes from a scatter of named beds rather than one deposit. Go with a full-size spare, more water than you think, and a downloaded map, because there is no cell service across most of it and the roads turn to grease when it rains.
Straight answers
- Is it worth cutting?
- Cuts and polishes very well. Watch for hairline fractures from the desert freeze-thaw cycle, which are invisible in rough and ruin cabs.
- What is it really worth?
- Moderate for good picture material, higher for pieces with a convincing scene. Old rough from named beds outsells new material.
- Can you legally keep it?
- Largely BLM land, open to personal-use collecting, but claims are scattered throughout and some of the best beds are actively held. Look for claim markers before digging.
Often confused with
Owyhee Jasper vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Biggs is sharper and browner, Owyhee softer and bluer. Side by side it is obvious; from memory it is not.
How to tell apart: Morrisonite comes from the same general country but is a different animal: bold orbs and swirls in blue, green and brown rather than horizontal layering.
Often found alongside owyhee jasper
Minerals reported to co-occur with owyhee jasper. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6.5-7
- Density
- 2.6-2.7 g/cm³
- Streak
- White
- Luster
- Waxy to Dull
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Rhyolite
- Typical price
- $5-50 for small slabs, higher for high-quality finished cabochons
Where rockhounds find owyhee jasper
Classic worldwide localities
- Owyhee County, Idaho, USA
Field-hunting tip
Look in rhyolite country, the host setting where owyhee jasper typically forms. If you start seeing quartz, chalcedony, calcite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify owyhee jasper?+
Where is owyhee jasper found?+
How much is owyhee jasper worth?+
What rocks look like owyhee jasper?+
What minerals are found with owyhee jasper?+
What kind of rock does owyhee jasper form in?+
What is owyhee jasper used for?+
Find owyhee jasper on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
