Donnybrook Bed

The Donnybrook Bed, located in Malheur County, Oregon, is a classic and well-regarded thunderegg site known for producing nodules with complex, eye-catching interiors. Thundereggs from Donnybrook often contain richly colored agate in shades of red, orange, gold, and gray, frequently accompanied by moss or dendritic inclusions. Some specimens also feature quartz or chalcedony-filled voids, adding extra visual interest when cut. The rhyolite matrix tends to be coarse and reddish, and the eggs themselves are typically solid and well-formed—ideal for lapidary work. Donnybrook material is sought after for its combination of vibrant color, internal variety, and cutting quality, making it a favorite among seasoned collectors.