Simply put, a Petoskey Stone is an extinct fossilized coral. Why is it called, “Petoskey Stone”? Because they are found in abundance in and around Lake Michigan shores, especially near the Northern Michigan city of Petoskey (USA)! The name “Petoskey” is the English adaptation of an Ottawa Indian Chief Petosegay, which is said to mean “The Rising Sun”!

They are also called “lucky stones” by many because finding these ancient coral fossils, remnants of prehistoric reefs, feels like discovering a special piece of history!

How could the remains of a coral, which thrived in tropical warm waters, possibly find its way to the cool regions of Michigan? So, during the prehistoric Devonian time period around 416 to 369 million years ago when the Petoskey Stone corals thrived, the dominant landscape of North America lay nearer to the equator and the entire earth was more tropical. Consequently, risen, warm, shallow seas covered a large portion of the continent, including Michigan. Later, the coral remains were buried under deep layers of sediment. Many millions of years after that when the great glaciers retreated northward, they scraped and dug into those forgotten layers of earth freeing them from trappings. The glaciers released and deposited them where we can now enjoy the good fortune of discovering their mysteries.

Petoskey Stone fossils originate from mass coral colonies of Hexagonaria, percarinata. Each hexagonal corallite (visible in the stone) held a single animal which opened a mouth exposing tentacles that siphoned food particles floating by in ocean currents. The tentacles were also used to sting any organism or other corallites that came too close. Calcite, silica and other minerals replaced the original exoskeleton over many millions of years.

PETOSKEY STONE CLASSIFICATION

Common Name: Petoskey Stone or Lucky Stone

Scientific Name: Hexagonaria, percarinata

Kingdom: Animalia

Phylum: Cnidardia (means to sting)

Class: Anthozoa (ie coral, sea pens, sea anemones)

Subclass: Zoantharia (true corals)

Order: Rugosa (means wrinkled wall)

Family: Hexagonaria (means six sides)

Species: percarinata

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