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Illinois Earth Symbols

Illinois State MineralFluoride, with Italy’s famous Dolomite Mountains in the background.

Illinois’ earth symbols may be as odd as Abraham Lincoln.

Fluorite (aka fluorspar) is Illinois’ official mineral. Illinois is the largest producer of fluorite in the United States.

Fluorite is a colorful mineral, both in visible and ultraviolet light. This makes it valuable in ornamental and lapidary uses. However, it is more widely valued for industrial uses.

Fluorite is also the source of fluoride, which is added to drinking water in the U.S. to prevent tooth decay. But if fluoridation is such a good thing, why do so few other countries practice it?

In fact, people have been debating the benefits of fluoride for years. Some claim it’s good for your teeth but bad for your brain. Some people even claim the government puts fluoride in our drinking water as a form of mind control.

I will probably discuss fluoride in one or more books in my conspiracy science series. See

In 2023, Illinois legislators snubbed sandstone and limestone and named dolostone the state rock.

The most famous dolostone lends its name to Italy’s Dolomite Alps. Illinois’ dolomite isn’t nearly as spectacular. However, it is 400 million years old. At that time, what is now Illinois was the floor of a tropical sea. The remains of ancient marine creatures were transformed into limestone, which in turn transformed into dolostone. Today, dolostone is heavily quarried in Illinois for use as a building material.

Fossil ˆ

Illinois State Fossil

While you’re pondering ancient seas and fluoride, take a look at Illinois’ state fossil, the Tully monster. This alien creature is named for Francis Tully, who discovered it in 1958. The bizarre aquatic beast lived about 307 million years ago. Unable to identify it, scientists simply called it “Tully’s monster.”

Finally, scientists decided it’s related to lampreys. Lampreys are a type of fish considered among the most primitive living vertebrates. In fact, some scientists aren’t sure if they should even be considered vertebrates.

Not everyone agrees that the Tully monster was a cousin of the lamprey. It certainly doesn’t look like a lamprey.

Soil ˆ

Illinois State SoilLeft: kestrels nesting in a wall of loess.

Meet Illinois’ most important state symbol, Drummer soil. The deep, dark black topsoil was named for Drummer Creek (in Drummer Township, Ford County, Illinois).

How deep is deep?

These prairie soils formed in 40-60 inches of loess—fine wind-blown sediment. Loess is particularly associated with glaciers. But the closest glaciers to Illinois are in the Rocky Mountains.

During the Ice Age, however, huge continental glaciers surged across what is now Illinois, grinding bedrock into dust. This is the source of the prime ingredient that makes Drummer soils such a treasure.

Drummer soils are the most prevalent soils in Illinois, occurring on more than 1,500,000 acres in northern sections of the state. They are also Illinois’ most productive soils.

The next time you enjoy an ear of organic sweet corn, be sure to give thanks for the Ice Age prairie soils that nurtured it.

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