“.. One of the few areas in the Ochocos where the eggs are jasper filled rather than agate filled. The jasper can range from a solid dark brown to a light yellow, sometimes in the same egg. The most desired colors are the pale blue, mauve and magenta, especially if they occur on a lighter background color of jasper. The jasper can tend to fracture, as it is more brittle than agate. Some of the specimens from here can be quite large and have many chambers of different colored jaspers. The matrix is normally a very light creamy color. This area is a free digging location...”

 extract of the article from Mark Ketsdever, Hillsboro, Oregon, 2007 :”Thunderegg Agates of the Ochoco Mountains, Oregon, USA”

This Jasper is called Morrisonite Jasper as well as the Morrissonite from the Malheur County in Oregon

Very fine jasper-specimen from Oregon are presented on the jasper-websites of Hans Gamma at  www.worldofjaspers.com