Trilobite

Trilobites were an ancient marine arthropod related to modern crustaceans. They had segmented calcite shells and were one of the first animals to develop complex eyesight and some species could roll in a ball for defense. Trilobites date back to around 520 million years ago during the Cambrian period and lived for about 300 million years before going extinct in the Permian period about 250 million years ago during a mass extinction event on earth referred to as the “Great Dying”. They taught us a lot about early life and fossils today can be found in sedimentary rock across North America, Europe, Asia, and Morocco. Their remarkable detailed and well preserved fossils make them highly treasured by scientists and collectors

Hardness: 6.5 – 7
Composition: SiO₂