Agate Dinosaur Bone Sphere
Morrison Formation
Upper Jurassic
Utah

This is a top-quality example of agatized dinosaur bone from the Morrison Formation of Utah. The fossilized internal structure of the bone is perfectly preserved. The specimen is most likely from a sauropod dinosaur and probably from the distal end of a limb bone. The vivid colors are caused by trace amounts of uranium minerals that were present during the fossilization process. The sphere is 8 cm in diameter.