If you have the opportunity to walk along the western shorelines of Michigan’s lower peninsula, you may find both Petoskey and Charlevoix stones scattered there. Both of these fossilized coral specimens abounded during a time when the region was covered by a warm, shallow sea teaming with reef life.
Difference Between Petoskey Stone and Charlevoix Stone
So what is the difference between a Petoskey Stone and a Charlevoix Stone?
Petoskey stones, the state stone of Michigan, actually had a shorter period of existence than the Charlevoix. Petoskey fossils are distinguished by a large, hexagonal corallite pattern, with a central “eye” and a radiating sunburst pattern.
In many specimens, eight to ten Charlevoix corallites could fit in one Petoskey corallite. Petoskey stones are coveted by many for the detailed image created after polishing. The large hexagonal pattern gives an almost 3D impression of what the living creature may have been like.
Read More: How To Polish Petoskey Stones
Petoskey and Charlevoix stones originate from two now-extinct groups of coral. Petoskey is from the genus Hexoganaria in the Rugosa group, Charlevoix from the genus Favosite in the Tabulata group. Both corals are named for towns along the coast in that part of Michigan where they are most abundant.
The Charlevoix stone’s smaller corallites are generally lighter or white in color. The tiny corallites may appear empty or include some radiating lines which do not reach the center. Charlevoix specimens more frequently display a side view of long coral tubes with the fossilized coral polyp at the end. These polyps form the fossil’s well-known honeycomb pattern.
Charlevoix stones existed for nearly four times as long as Petoskey stones. Both stones are believed to have thrived before the dinosaurs, snagging the warm sea’s plankton with their tiny tentacles. The fossilized remains were pushed along during receding glacial activity at the end of the last ice age. The stones came to rest along the floor of Lake Michigan.
Where To Find Charlevoix and Petoskey Stones
Each winter, lake ice stirs up the lake bed and shoreline, exposing more stones to avid rockhounds after the spring thaw. Storms may also wash more specimens onshore. The stones can be found on rocky beaches, but it can take a bit of patience to locate them in their rough state among so many pebbles, so allow yourself plenty of time for the expedition.
The stones are popular among rockhounds near and far. The two stones are easy to differentiate once you’ve seen an example of each. Beachcombers search for the stones to add to their collection or polish for jewelry or other collectibles. Both Petoskey and Charlevoix stones may be found in shops along the lakefront as well as many online sites.