Septarian Nodule (Utah)
A type of geode, Utah Septarian Nodules are found about 15 miles east of Zion National park. They were formed in an ancient sea floor during the Cretaceous period, 50-70 million years ago. As they weathered out of the gray clay hills, at one time, they could be picked up on the surface. Now, bulldozers are required for their extraction, usually 20-30 feet underground. Some geodes are filled completely with calcite, while others are hollows showing calcite crystals.
The composition of the Septarian is as follows:
Yellow Centers - Calcite
Brown Lines - Aragonite
Grey Rock - Limestone
White or clear - Barite
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