sliced and polished, diameter 8" — 20.3 cm.
Provenance: Estate of Sonja Bata, Toronto
Note: This mass formed between 50 to 70 million years ago. As the ocean receded, balls of dead sea life and mud dried and cracked. As decomposed shells seeped down into the cracks in the mud balls, calcite crystals formed. The outer thin walls of calcite then transformed into aragonite. Septarians are composed of Calcite (yellow centres), Aragonite (brown lines), and the outer grey rock is Limestone.