THE PETOSKY STONE
Why is it called the Petoskey Stone?
The name Petoskey Stone likely came about because
it was found and sold as a souvenir from the Petoskey
area. The name Petoskey appears to have originated
late in the 18th century. Its roots stem from an Ottawa
Indian legend.
According to legend, a descendant of French nobility
named Antoine Carre visited what is now the Petoskey
area and became a fur trader with the John Jacob Astor
Fur Company. In time, he met and married an Ottawa
(or Odawa) Indian princess. Carre became known to
the Indians as Neaatooshing. He was eventually adopted
by the tribe and made chief.
In the spring of 1787, after having spent the winter
near what is now Chicago, Chief Neaatooshing and his
royal family started home. On the way, the party camped
on the banks of the Kalamazoo River. During the night,
a son was born to the Chief. As the sun rose, its
rays fell on the face of the new baby. Seeing the
sunshine on his son's face, the Chief proclaimed,
"His name shall be Petosegay. He shall become
an important person. " The translation of the
name is "rising sun," "rays of dawn,"
or "sunbeams of promise".
In the summer of 1873, just a few years before the
death of Petosegay, a city came into being on his
land along the bay at Bear Creek. The site was a field
overgrown with June grass. Only a few nondescript
buildings existed. The population was no more than
50 or 60. The city was named Petoskey, an English
adaptation of Petosegay. Thus they honored someone
who gave his land, name, and the heritage of "sunbeams
of promise".
Today, Petoskey is a growing city with all of the
comforts of modern life and an appreciation of the
past. Here is where Petoskey Stones are most commonly
found. For those who look, Petoskey Stones are along
the beaches, inland in gravel deposits, and sold in
gift shops.
How was the Petoskey stone formed?
So, what is a Petoskey stone? It is a fossil colonial
coral that lived in the warm Michigan seas during
the Devonian time around 350 million years ago. The
name Hexagonaria (meaning six sides) percarinata was
designated by Dr. Edwin Stumm in 1969 because of his
extensive knowledge of fossils. This type of fossil
is found only in the rock strata called the Gravel
Point Formation. This formation is part of the Traverse
Group of the Devonian Age.
During the Devonian time, Michigan was quite different.
Geographically, what is now Michigan was near the
equator. A warm shallow sea covered the State. This
warm, sunny sea was an ideal habitat for marine life.
A Devonian reef had sheltered clams, cephalopods,
corals, crinoids, trilobites, fish, and many other
life forms.
The soft living tissue of the coral was called a polyp.
At the center of this was the area where food was
taken in, or the mouth. This dark spot, or eye, has
been filled with mud of silt that petrified after
falling into the openings. Surrounding the openings
were tentacles that were used for gathering food and
drawing it into the mouth. The living coral that turned
into the Petoskey stone thrived on plankton that lived
in the warm sea.
Calcite, silica and other minerals have replaced the
first elements of each cell. Each separate chamber,
then, on each Petoskey stone, was a member of a thriving
colony of living corals. For that reason the Petoskey
stone is called a colony coral.
The picture below illustrates the six sided formation
left from the living coral colonies found on the Petoskey
stone. These stones are polished and therefore display
the fossilization even better. However, the wind and
waves and sand cause a polishing effect, and for this
reason stones found on the shores of the Bay have
a more polished look naturally.
However, when Petoskey stones are found inland, they
are unpolished and therefore less defined.
Where can you find the Petoskey stone?
The Petoskey stone can be found anywhere in the state
from the Traverse City area across the state to Alpena.
They can be found in gravel pits, and on road beds.
However, the biggest influx of stones are found on
and around Little Traverse Bay, from Charlevoix to
the town that gave the stone it’s name, Petoskey.
Pleistocene glaciers (about two million years ago)
plucked Petoskey stones from the bedrock and spread
them over Michigan and surrounding areas. This is
why Petoskey stones can be found in gravel pits and
along beaches far from the Petoskey area.
The best time to find the Petoskey stones is early
spring after the ice on Grand Traverse Bay has melted
along the shore. Each year as the ice is broken up
and the winds push the ice in different directions,
it pushes a new crop of Petoskey stones towards the
shores. The best time to find the stone in the summer
is after a wind storm or a misty rain, when the wetness
will make the fossil pattern of the stone more visible.
However, finding a stone might require some time and
patience, especially considering the influx of other
tourists seeking out the stones as well!
HOW TO POLISH PETOSKEY STONES BY HAND
And now for the real fun! Petoskey stones are made
up of calcite, and therefore are a good candidate
for hand polishing. Calcite is soft enough so that
it can be easily worked, but dense enough to take
a nice polish.
WHAT YOU NEED TO POLISH THE STONES:
Petoskey stone
Sandpaper (220, 400, or 600 grit)
A thick towel or newspaper
A piece of corduroy or velvet
Polishing powder
Water
Once you have found the stone you want to polish,
sand it down with the 220 the sandpaper mentioned
above. After rubbing, rinse the stone down and dry
it off. Examine the stone for scratch marks, and if
there are any, keep on sanding! All scratch marks
should be gone! Next, sand again with 400 grit sandpaper.
This should remove any coarse spots. Once again, rinse,
dry and check. Now sand the paper with the 600 grit
to make sure that the stone is smooth and scratch
free. When you think it looks perfect, continue sanding
for another 10 minutes, just to make sure. At this
point, it is time to polish. Sprinkle the damp corduroy
or velvet with polishing powder. A short, rotating
rubbing will polish the stone. However, if scratches
appear, start from the beginning with the 220 grit
paper to remove them! When you’re finished with
the polishing, simply rinse the stone off in clean
water, and dry. Now you have your own, hand polished
Petoskey stone!
This page was created by Emily Teske, a former GEO
333 student. Great job, Emily.
