A Petoskey stone .is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral that lived 350 million years ago. The rocks rounded in the surf along the shores of Lake Michigan near Petoskey, Michigan.
The living Earth (except a few times when I pin dead stuff) --- Sinosauropteryx: The first genus of dinosaur outside of Avialae (birds and their immediate relatives) to be found with evidence of feathers. Which can be seen clearly in this gorgeous fossil.
Bellevue Limestone - fossiliferous limestones with Streptaster vorticellatus edrioasteroid (left) and Carneyella ulrichi edrioasteroid (right) (middle Upper Ordovician) from near Maysville, Kentucky, USA.