Septarian

Septarians began their geological life ~70 million years ago when an inland sea reached from the Gulf of Mexico to the Arctic, covering Utah. Wave action rolled sea mud into balls. When the water receded, shell life died and balls of mud were left to bake in the sun where they hardened and cracked.

Time passed.

When the water returned, it forced its way inside the nodules carrying yellow calcite which is decayed shell material. A thin wall of calcite transformed into brown aragonite, separating gray clay exteriors from the yellow calcite centers.

These septarians were found near Muddy Creek in Orderville, Utah.

Single mud ball . . . slabbed

Same mud ball, showing polished interior slabs

A better view of some individual pieces

Natural Stone Art

of the American West