Septarian nodule. This is a round mineral deposit of claystone (grey) filled with cracks formed when the claystone dried up. These cracks fill with ot

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Septarian nodule. This is a round mineral deposit of claystone (grey) filled with cracks formed when the claystone dried up. These cracks fill with other minerals, often calcite, a form of calcium carbonate. The variety of patterns that can form are often prized for their beauty. This specimen, from the Appenine mountains, Italy, measures 450 millimetres in diameter.

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Size: 5125px × 3417px
Photo credit: © DIRK WIERSMA/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: appenine, ball, claystone, close-, concretion, cracked, cracks, detail, dried, europe, european, geological, geology, italy, mineral, mountians, nodule, rock, septaria, septarian, septarium, stone