petoskey stone in surf, photo by northernlightphotograph.

The 6th annual Antrim County Petoskey Stone Festival takes place on May 28, 2011 in Barnes Park in Eastport. The Petoskey Stone is of course Michigan’s state stone.

Almost a century after the founding of Petoskey, on June 28, 1965, Governor George Romney signed a bill that made the Petoskey Stone Michigan’s official State Stone. It was fitting that Miss Ella Jane Petoskey, the only living grand-child of Chief Petosegay, was present at the formal signing. The legislation is very general. The bill simply states that the Petoskey Stone is the State Stone. The designation of Hexagonariapercarinata was made by Dr. Edwin C. Stumm in 1969. Dr. Stumm made this distinction based on his extensive knowledge of fossils.

This specific fossil coral is found only in the rock strata known as the Alpena Limestone. The Alpena Limestone is part of the Traverse Group of Devonian age. The Alpena Limestone is a mixture of limestones and shales. The outcrops of these rocks are restricted to the Little Traverse Bay area near Petoskey.

Check this out bigger and in Tim’s slideshow. See more of Tim’s photos on Michigan in Pictures.

You can read the story behind the Petoskey name on Michigan in Pictures (and learn about the little known holiday “Throw in a Petoskey Stone Day”).