This interesting colorful silica agate with jasper unique and wild patterns, it is called Purple Cow Jasper. This cabochon does not have the purple color. This was mined years ago near McDermitt, Nevada. Considered rare as it is hard to come by this material. Even harder to come by the old true purple and red colors. There is more of a tan and brown color out there. Which was found deeper down at same site.
 
Flat polished beveled back
Measures 27.20x45.20mm
Thickness 6.70mm