Z Stones are biological and mineral time capsules. Born 40 million years ago at the bottom of the ancient Tethys Sea, they began life as clusters of Marcasite and Pyrite nodules, often replacing prehistoric sea sponges or urchins.

As the sea receded and the White Desert was born, a process called pseudomorphism occurred. Oxygen-rich water leached out the sulfur molecules and replaced them with Iron Hydroxides—transforming the stone into Limonite while perfectly maintaining its original geometry.