Septarian Nodule Egg
Add this Septarian Nodule Egg to your fossils collection. This opened egg displays black druzy crystals with tiny Calcite crystals.
A Septarian nodule is a type of concretions that is formed when cracks appears in the nodule due to shrinkage and are filled with crystals deposited from percolating brines.
The dark patches are calcareous material, the pale ones in the cracks are Calcite.