Septarian - Heart

A Septarian heart from Utah, USA, with star-shaped, jagged cavities filled with yellow calcite.

Septarian nodules are sedimentary concretions of clay, lime, and aragonite, which develop star-shaped cracks internally due to shrinkage. These cracks are later filled with crystallized calcite, a characteristic structural feature.

The heart was cut from a round Septarian nodule and polished on both sides. The crystals in the cavities are natural and untreated; the polish only affects the outer rock.

Utah is the classic region for finding Septarian nodules of this quality. A documented collector's unique piece with clear stratigraphy between the concretion and the calcite filling.