Bruneau jasper is a variety of the mineral

jasper Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref> ...

. It is a "picture jasper" – a jasper that exhibits particular patterns and colors – and is used as an opaque gemstone. The stone exhibits layered patterns of brown, reddish brown and cream color, or sometimes of red and green color. It was discovered in the

Bruneau River The Bruneau River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. tributary of the Snake River, in the U.S. states of Idaho and Nevada. It runs through a narrow canyon cut into ancient lava flows in sout ...

canyon in

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyomi ...

, near the bottom of the canyon walls, where the rhyolite in which the jasper occurs is exposed for a length of . As of 2009 Bruneau jasper was no longer in production, and was difficult to locate.

References

{{mineral-stub Jasper Geology of Idaho