To Each His Own Rock

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I like rocks. Coming from a country and farm girl, you may think that is an absurd thing to say, especially since I spent an entire summer picking rocks (a lot of which were actually boulders) to clear more farm ground. However, they have always fascinated me. Each one is unique, you can decorate with them, and unlike other landscaping techniques, they’ll never need water or any special care.

Each area has its own specific kind of rocks for which it is known, which makes hunting for them just as much fun as having them. Not to be partial, but there are four distinct rock formations that catches my eye.

First and foremost is the pudding stone. Anyone that has ever visited our yard knows that this was Jim’s favorite. He spent days driving the backroads and talking to farmers in pursuit of the elusive pudding stone. He even went so far as to ask that one be put on an estate auction and bought it! Another he got free, but paid $250 to have it hauled here. Now that is the love of a rock!

Pudding stones can be found here in southwest Michigan, although the hot spot in the state for them is on Drummond Island. The island itself is known as the “gem of the Huron, and at her center is the Pudding stone.” The glaciers pushed them down through eastern Michigan and along the north shores of Lake Huron.

They are so named because they look like big globs of pudding, predominantly pink in color, with bands of smaller stones distributed throughout the larger rock. They are conglomerates of quartzite and pebbles of jasper, and their size ranges from as small as a pebble to as large as a dump truck. The British settlers that were stationed on Drummond Island believed that they looked like boiled sweet pudding with berries, hence their name.

Pudding stones found their beginnings about a billion years ago, when great amounts of sediment from the erosion of other rocks were deposited in large bodies of water. Different hues of red jasper pebbles were deposited in small portions over an east/west band about 50 miles in size that lays mainly in Ontario, but trickled down to smaller areas of the Upper Peninsula. These pebbles became embedded in the sediment. Some of these smaller pebbles have even been gold and sapphire.

Our pudding stones range in color from black to white, grey, pink, and everything in between. In my neck of the woods, finding a pudding stone is like finding a gemstone.

Geodes are another favorite of ours. They may be ordinary and drab on the surface, but they’re full of crystallized minerals on the inside which makes them irresistible whether you are a rock fanatic or not.

Geodes usually see their beginnings when a cavity forms in a rock which can happen in several ways. They are most common in igneous rocks, which are created by cooling lava. In most instances, a bubble of carbon dioxide and water vapor forms in the lava, like bubbles in a carbonated beverage. As the rock cools and gas dissolves, a cavity is formed. They are also formed in sedimentary rock like limestone and sandstone when minerals like coral, fossils, and pieces of wood begin to dissolve and, over time, leave a shell waiting to be filled. Groundwater seeps through the porous rocks, and additional mineral layers are deposited in the hollow interior. Over thousands of years, these layers of minerals build crystals that eventually fill the space inside. Large geodes can take 1,000,000 years to form.

Although geodes can be found anywhere, the hot spots are in the Midwest states of southern Indiana, Kentucky, Ohio, Missouri, and Iowa. Many times they are in streams, since running water is needed for their formation. People in the area hunt these like treasure and sell them in gift shops and the like. We gave in and bought a few while we were in southern Indiana, as we tried our hand at looking for them to no avail. Part of the reason for this is that they look like ordinary round or oval rocks with lumpy surfaces. The only way to find out if they are the real gems is to break them open.

A few weeks ago, we spent the better part of a day looking for agates at Whitefish Point on Lake Superior in Michigan’s Upper Peninsula. Agates are semi-precious, variegated gemstones. They develop when empty pockets inside a host rock fill in molecule by molecule, layer by layer, as microscopic quartz crystals self-organize to form concentric bands or other patterns. Color and arrangement are influenced by changes in air pressure, temperature, and mineral content that occur during formation.

Unlike other gemstones, each agate is unique, and even slabs cut from the same rock will vary in color and design. For thousands of years people have believed that agates have metaphysical properties to enhance life and cure disorders. This includes such powers as preventing insomnia, protection from disease, and promoting good agricultural crops.

The pristine waters of Lake Superior always wash up an interesting array of rocks, and its shoreline usually yields a good share of agates. We came home with a 5-gallon bucket of beauties, but no agates. This just means another trip back for us!

You can’t live in Michigan without feeling a connection to the Petoskey stone. They are fossilized corals that lived in the warm shallow seas that covered Michigan 350 million years ago. Sheets of glacier ice plucked the stones from the bedrock, ground off the rough edges, and deposited them around the city of Petoskey. The dry rocks resemble ordinary limestone but, when polished, the distinctive mottled pattern of the 6-sided coral fossils emerges.

Legend and history are combined in the Petoskey stone. The stone is named after the city of Petoskey, and the city is named after the Ottawa Indian chief, Pet-O-Sega. In 1965, the Petoskey stone was named the state rock of Michigan.

Not a native of Michigan, but rather of Missouri, the rose rock has earned a place in my heart since Phyllis Batten graciously shared one of hers with me last week. They are sought after and prized worldwide because of their beautiful, rose-like appearance.

Rose rocks are crystal clusters of gypsum or barite, which include abundant sand grain. The petals are flattened crystals fanning open in radiating, flattened-crystal clusters. They are only found in a few rare places around the world, and most in The States come from Oklahoma. An old Cherokee legend says that the rocks represent the blood of braves and the tears of the maidens who made the devastating “Trail of Tears” journey in the 1800’s to Oklahoma.

To me, rocks represent history and continuity, even though each one is unique and individual. I like the way they look and the way they feel. They are a source of permanence. I guess once a rock hound, always a rock hound. Besides, rocks give us the perfect excuse to go on excursions in search of that one special one that is just waiting to become the next addition to our yard.