Michigan: Petoskey Stone (state stone)
Michigan: Petoskey Stone (state stone)
Michigan boasts both a state fossil and a fossil for its state stone, and was the first state in the nation to designate a fossil as an official symbol. The Petoskey Stone was named the state stone four years before the coral species it is made of was scientifically described!
Petoskey Stones are common in the northern part of the Lower Peninsula, and are actually fragments of Devonian Period coral reefs. These reefs grew in what is now Michigan about 360 million years ago, when the area was covered by a shallow sea. The particular species of coral represented is Hexagonaria percarinata, an example of what is known as a tabulate coral, one of two main types (along with rugose "horn" corals) that made up the reefs of the Paleozoic Era. Both tabulate and rugose corals were decimated at the end of the Paleozoic, and replaced by the scleractinian corals which are common in reef environments today.
Michigan was extensively resurfaced by glaciers during the Pleistocene (the last 1.6 million years), and as part of this process, moving glaciers plucked up pieces of the bedrock and carried them along, smoothing and rounding them in transport. This accounts for the regular shapes of Petoskey Stones found today. Good Petoskey Stones may be collected at Fisherman's Island State Park near Charlevoix, and at the south end of the beach at Petoskey State Park. In the late 1990s, the largest Petoskey Stone yet discovered, a one-ton monolith, was found by an amateur fossil hunter at Sleeping Bear Dunes National Lakeshore.
According to an Ottawa legend, the town of Petoskey was named for Pe-tos-e-gay, a wealthy fur trader who was the son of a chief. His only living granddaughter, Miss Ella Jane Petoskey, was on hand for the governor's signing of Public Act No. 89 on June 28, 1965, designating the Petoskey Stone the state stone of Michigan.
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