(Internal # R591-11) This is genuine piece of Septarian slice, specimen from Utah with 2 flat sides, 6-3/8" diameter x average 1/2" thick. Weighs 1 pound 5.1 ounces. Absolutely beautiful. Yellow center = Calcite Brown lines = Aragonite Gray rock = Limestone One side polished to a high sheen; these work well as coasters for the coffee table, or lovely display pieces What you see in to photo is what you get. SEPTARIAN NODULE specimens Septarian nodules are found 15 miles E of Zion National Park, Utah. They were formed in an ancient sea floor during the Cretaceous period, 50-70 million years ago when the Gulf of Mexico extended into Utah. On the ocean floor, mud formed around decomposed sea life. Rocking back and forth in the water caused mud balls. When the ocean receded, the mud balls dried and cracked open. Over the eons to follow, mineralized solutions deposited in the cracks. First forming brown ARAGONITE, then golden CALCITE and occasionally BARITE clusters were formed within the cavities. The outside of the mud ball is now a gray limestone rock. As the nodules weathered out of the gray clay hills, at one time they could be picked up by hand on the surface. Now, excavating equipment is required for extraction, 20-40 feet underground. The name "Septarian" is Latin "Septem" meaning seven. The mud balls cracked with seven points in every direction, creating a beautiful design. The fossil which started forming the Septarian nodule is sometimes noticeable in the rock. WE SHIP WORLDWIDE, see the chart for postage to your country. Click on our Store tag for SIMILAR items.