A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized rugose coral, Hexagonaria percarinata. [1]

Sep 24, 2020 · Petosky stone is a fossil rock formed from the remains of the rugose coral Hexagonaria percarinata. These corals are believed to have existed before the dinosaurs and thrived during a time when a warm, shallow sea covered a large part of the Great Lakes region.

Jun 3, 2022 · Once-living coral, Petoskey stones (the official state stone) remain a beloved symbol of our Great Lakes from more than 350 million years ago. Luckily, for rock-hounds and fossil-hunters, the shores of Michigan are vast.

Where to Find Petoskey Stones in Michigan. The Petoskey stone, Michigan’s state stone - and its lesser-known cousin, the Charlevoix stone – are unique to the Great Lakes and can be found along the shores of Michigan’s lower peninsula.

Apr 13, 2024 · Petoskey Stones are unique fossils made of ancient coral found on Michigan beaches and in gravel deposits. To find these stones, look for pebble shapes with hexagonal patterns on Lake Michigan beaches or join a rock hunting club for tips and exclusive locations.

Nov 11, 2023 · Petoskey Stone is a fossilized coral, specifically a type of colonial coral known as Hexagonaria percarinata. The stone gets its name from the city of Petoskey in Michigan, where it is commonly found.

Petoskey stone is a fossilized coral. It's a unique rock found in Michigan and is Michigan's official state stone. The coral it's made from is called Hexagonaria percarinata and lived in a warm, shallow sea millions of years ago. The stone's distinctive pattern of six-sided "rays of the rising sun" is revealed when it's wet or polished.

Aug 7, 2023 · Petoskey stones are a popular Lake Michigan beach find along with beach glass and Yooperlites. To paleontologists, this coral truly does not become a “Petoskey Stone” until someone slices and polishes it (and charges people lots of money for it).

So, what is a Petoskey stone? It is a fossil colonial coral that lived in the warm Michigan seas during the Devonian time around 350 million years ago. The name Hexagonaria (meaning six sides) percarinata was designated by Dr. Edwin Stumm in 1969 because of his extensive knowledge of fossils.

The prehistoric fossil, unique to the Traverse Group rock strata, is called the Petoskey Stone and is Michigan’s official state stone. A Petoskey Stone consists of tightly packed, six-sided corallites, which are the skeletons of the once-living cor-al polyps.