Petoskey Stone Legend

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. This type of fossil is found only in the rock strata called the Gravel Point Formation. This formation is part of the Traverse Group of the Devonian Age.

During the Devonian time, Michigan was quite different. Geo-graphically, what is now Michigan was near the equator, at a time when all of the continents were still together. A warm tropical sea covered the state. This warm, sunny sea was an ideal habitat for marine life.

A Devonian reef had sheltered clams, cephalopods, other corals, crinoids, trilobites, fish, and many other life forms. The soft living tissue of the “Hex” coral was called a polyp. At the center of this was the area where food was taken in, or the mouth. This dark spot, or eye, has been filled with mud or silt that petrified after falling into the openings. Surrounding the openings were tentacles that were used for gathering food and drawing it into the mouth which can be seen by the lines in the stone itself. The living coral that turned into the Petoskey stone thrived on plankton that lived in the warm sea. Calcite, silica and other minerals have replaced the first elements of each cell. Each separate chamber, then, on each Petoskey stone, was a member of a thriving colony of living corals. For that reason the Petoskey stone is called a colony coral.

Just about on every Petoskey Stone is sparkly crystals that can be seen in the mouths, sometimes in a group which can resemble an “eye”, and even lines running through, although sometimes it can look like a crack in the stone if the crystal is missing. The crystal is actually Quartz. Quartz is a natural filter which is why sometimes you can find other minerals including gold. You will also find Petoskey Stones in different colors like white, brown, etc. It’s been said that stones that have a caramel color when polished are stones that when alive were from around the Little Traverse Bay and surrounding area.

Is Petoskey Michigan the only place to find stones? The answer is no. Again, as time went by and the continents separated, the water receded and we ended up with fossilized coral. Our area has also had several ice ages which created the Great Lakes and pushed these stones all over, so stones can be found at times on the east side of the state, southern part and even into Indiana, Illinois.