Michigan’s State Stone – Petoskey Stone
Michigan’s State Stone, the Petoskey Stone, may be found along the shores of Michigan’s Lower Peninsula, as well as in glacial drift throughout Lower Michigan. It is used for making jewelry and ornaments.
From a Postcrossing pal in Michigan
What’s a Petoskey Stone?
The Petoskey Stone is a coral that lived 350 million years ago during the Devonian age when the northern part of Michigan was covered with a sea of warm water. The scientific name is Hexagonaria percarinata (Hexagonaria meaning having six sides).
The soft living tissue of the corallite was called polyp. At the center of the polyp was the food intake opening or mouth. This dark spot, or the eye of the corallite, has been filled with silt or mud that petrified after falling into the openings. Surrounding the opening were tentacles that were used for gathering food and drawing the food into the mouth. This living corallite thrived on plankton which lived in the warm sea.
Calcite, silica and other minerals have replaced the original elements in each cell. Each chamber or corallite at one time was a living marine animal that grew in colonies. The Petoskey stone is also known as a colony coral. -From Potoskey Area website