Septarian Stones/Septarian Nodules are concretions that are believed to have formed during the Cretaceous period. Septarian stones are sandstone nodules that were formed by the movement of the tides. As the water levels receded, the nodules dried out and cracked. Over time calcite and aragonite filled the cracks, creating the brown and yellow patterns found inside.
This specimen is a 10.4-ounce piece of Septarian Nodule that has been cut and beautifully polished in our lapidary workshop.