A-L: UTAH'S FLUORESCENT SEPTARIAN NODULES w CALCITE +

Location of Mineral Deposit:  MT. CARMEL, ZION NATIONAL PARK AREA, ORDERVILLE,  UTAH

Description:  These Septarian Nodules can be full of Calcite crystals that Fluoresces a Pale Yellow color under a Shorwave Ultra Violet Light and a brighter Yellow Gold color under a Longwave Ultra Violet Light and they are a yellowish is color in the day light. There can be some Barite crystals that could Fluoresce a Pale White color and would appear White or Clear in the day light as well. The Aragonite Fluoresces a Tan color under a Longwave Ultra Violet Light and is Phosphorescent under both Shortwave and LongwaveUltra Violet Light and appears with Brown lines in the day light. The Gray portion is Limestone and is NON-Fluorescent.

The Utah Septarian Nodules are found about 15 miles east of Zion National Park, Utah near MT. Carmel.  They were formed in an ancient sea floor during the Cretaceous Period (30-70 million years ago). These calcite septarians are found in a river bed in Southwestern Utah.

These Nodules like this one were formed when Utah was underneath an ocean. The cracked mud balls were covered by calcium enriched waters which began to precipitate calcite and aragonite inside of these mud balls.  As the ocean receded, the balls were left to dry and cracked. Because of their bentonite content they also shrank at the same time trapping the cracks inside.  A thin wall of calcite was transformed into aragonite separating the bentonite heavy clay exteriors from the calcite centers.

The resulting pattern of crystallization is beautifully shown when the septarians are cut and polished. The name septarian comes from the fact that there are always seven outward cracks in these mud balls As they weathered out of the gray clay hills, one at a time, they could be picked up on the surface.  Now bulldozers are required for their extraction, usually 20-30 feet underground.

  For more information on this specimen, check out page 134 in an outstanding book called "Collecting FLUORESCENT MINERALS"    by Stuart Schneider 2004 edition.