The Petoskey Stones are composed of petrified skeletons of Hexagonaria percarinata. This is a type of coral from coral reefs that once well covered all of what is now the state of Michigan, the USA, during the ancient Devonian period, around 350 million years ago.
The Petoskey stones were molded as a result of glaciation. sheets of ice scrapped the bedrock, gathering up fragments, and then grinding off their uneven edges and putting them in the northwestern portion of Michigan’s Lower Peninsula.
Ultimately, Petoskey stones are just chunks of coral reef, and when they dry, the stone looks like normal limestone, but when wet or polished, the characteristic mottled pattern of the six-sided coral fossils emerges.
This primeval fossil is brought into being across the state of Michigan along lakeshores and rivers in sediments usually called the Traverse group. Meanwhile, in 1965, the Petoskey stone was called Michigan’s official state stone. Therefore, more than 350 million years ago, during the Devonian period, Michigan was quite dissimilar.
Geologically, the region was located near the equator and covered by a warm, shallow, saltwater sea, wherever the colonial coral hexagonaria percarinata flourished with other marine life in tropical reefs. Moreover, then the earth’s plates moved and pushed Michigan north and above sea level.
When glaciers came about two million years ago, the land was scraped, and the fossils spread across the northern Lower Peninsula. The stone was named Petoskey because it was brought into being in great profusion in the Petoskey area.
Well, the name Petoskey derives from “Petosegay”, the son of an 18th-century Ottawa chief, and it means “rays of dawn” or “sunbeams of promise.” The city of Petoskey was also named after the same person. However, some say the coral pattern in the stone resembles sun rays radiating from small suns.
As the skeleton of once-living organisms, hexagonaria percarinata is composed of firmly packed, six-sided corallites. At the center of a piece of corallite was the mouth, enclosed by tentacles that were used for collecting food and drawing the food into the mouth. This dark spot, or the eye of the corallite, has been filled with silt or mud that petrified after falling into the openings. Calcite, silica, and other minerals have swapped the original soft tissues, called polyps, in each cell.
Petoskey stones can originate from the shores of Traverse City, north to the Charlevoix and Petoskey areas, and across the state to Alpena, but the most popular place to hunt for them is at Lake Michigan Beach. Spring is a good time to look for the stone after the ice has melted and uncovered specimens that they’ve pushed against the shore. Also, Read! Dragon Blood Tree
Source: Amusing Planet
