I've got a pretty big pile of McDermitt picture jasper, AKA Disaster Mtn. Jasper. It's got lots of wild designs but is fairly soft as far as jaspers go. I got it from an estate of an old rockhound.
Anyway, I was pawing through my pile one lazy saturday afternoon and I came across a piece that wasn't like the others. It was heavier and the coloration was different. On the saw it went, and what came out the other side was the discovery of a beautiful piece of Biggs Jasper.
Biggs is much more dense, and polishes to a porcelain finish with great scenic designs. It comes from an area near Biggs Junction Oregon.
For more on Biggs Jasper.