With the lake water levels up in all the Great Lakes, it’s been a time of change and discovery. The shifting sands have revealed sunken ships that we never saw before. The high water has caused erosion which has forced shoreline owners to erect seawalls along the beach. It also changed the minds of some folks who decided not to put up boat hoists in the bay fearing they would never see their boat again if a fierce storm blew in.
However, the high lake levels have also revealed a new abundance of small Petoskey stones in Saginaw Bay. These are mixed in with the small pebbles and gravel at the water’s edge. Especially near new seawalls. This is kinda a new thing in the beach areas between Sleeper and Port Crescent State Parks.
Why Are Petoskey Stones Suddenly So Prevelent On Saginaw Bay?
The truth is that the stones have always been prevalent in Saginaw Bay. Just they were buried by sand and silt. The high lake levels have moved some of the sand around to reveal gravel beds. However so has all the work on erecting hundreds of sea walls along the shore. The net result is that these little fossilized wonders are seeing the light of day.
Erosion from high lake levels reveals hidden stones every 20 to 30 years. When the water levels recede, the beaches will be almost devoid of stones. Even today, it’s easy to find them since the water is revealing them as it rises. All you have to do is take a few steps into the water.
These are small stones. Ideal for a quick polish and to make into jewelry.
What is a Petoskey Stone?
A Petoskey stone is a rock and a fossil made up of Hexagonaria percarinata, a fossilized rugose coral. It is commonly pebble-shaped. Glaciers ripped stones from the bedrock, ground down their rough edges, and deposited them in the northern portions of Michigan’s lower peninsula. Complete fossilized coral colony heads have been discovered in the parent rocks for the Petoskey stones in the same places of Michigan.
Petoskey stones are found in the Traverse Group’s Gravel Point Formation. They are coral reef remnants that were initially deposited during the Devonian period. The stone seems like an ordinary grey limestone when dry, but when wet or polished with lapidary processes, the mottled pattern of the six-sided coral fossils is revealed. These stones are used to make jewelry and other decorative items. Other types of fossilized coral such as the Cheboygan Stone are also prevalent in the northern Great Lakes.
How to Polish Petoskey Stones By Hand
Is it Illegal to Take Petoskey Stones?
This question was discussed by Mlive with a National Park Ranger. His suggestion was sound. Andrew Blake, acting chief ranger at Sleeping Bear Dunes National Park in Empire, advised against rock hunting in national parks. Collecting anything within the park is prohibited, and anyone caught doing so will face a hefty fine. “We mostly educate individuals and provide warnings, but we do issue tickets on occasion,” Blake explained. If you take any fossils or wood, you will be fined at least $325. At state parks, you are permitted to collect up to 25 pounds of rocks for each person.
Individuals may not take more than 25 pounds of rocks, fossils, or minerals per year from state parks, recreation zones, or the Great Lakes bottomlands in Michigan, according to state law.
Finding Petoskey Stones in Saginaw Bay
Tips and Tricks For Finding A Petoskey Stone
Find an uncrowded and fairly rocky stretch of Saginaw Bay or Lake Huron beach. It’s perfectly fine, and legal to wade in the shallow gravel area at the water’s edge. If you have a driver’s mask, bring that to see clearly in calm waters.
Take your time. After you find a few you will get better at recognizing the shape and color of the Petoskey stones and you will get tuned into just looking for them.
The best times to be looking. Because wave activity and winter ice have delivered new stones to the shores of Lake Huron, spring is often the best time of year to find Petoskey stones. Going out in the rain or right after a storm might prove productive in finding the little stones.
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