Green River Agate (chalcedony) Beds are in Emery County, Utah
The agate beds of southern Utah stretch from the San Rafael Swell to the west and to Moab to the east. Green River along I-70 is the northern boundary and it stretches to Hanksville on the south. This area produces a wide variety of agates, that even though vary, tend to all appear similar.

The terrain is mostly sandstone with localized beds of shale. Conglomerates are common and many contain pebbles of agate, petrified wood and bone

Closer toward the "Swell" is grape agate, plasma jasper, and Navajo jasper.




The grape agate nodules formed in a bed of shale. The agate nodule in matrix is about 10 inches across.



From the Hanksville area comes lots of agatized dinosaur bone, coprolite, wood, and pine cones. Along with lots of colorful chalcedony and pink to orange-ish red geodes.

Southwest of Green River is agate beds that are so prolific the agate pebbles can be raked up. Here the agate doesn’t form in bubbly formations but in pebbles of red, yellow, carnelian, sard, peach, tan, and many pastel colors.
Lots of it has a black desert varnish coating that once tumbled off produces spectacular specimens.



Before & after tumbling. The back one is about 1”.

Rare in this area are agatized coral pebbles that do polish.



The larger one is about 1”.

Just north of Moab is an area that produces mustard colored jasper with highlights of ketchup red.




Moab agate about 6” across.

This is in no way comprehensive of the agates of this area. Just a teaser about one of my favorite places on earth.

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