Hopewell Culture Mica

Written by Park Guide, Sarah Hinkelman

What brightens the color of paints, helped power the first fighter plane engines in World War I and was highly prized by the prehistoric Hopewell culture? The bright and shiny mineral mica, of course!

Mica is often thought to be a rock but is actually a group of minerals that occur in sheets or layers. Mica appears in the three major varieties of rock: igneous, sedimentary, and metamorphic. You might see it when you find a piece of quartz or granite that sparkles in the sun, the mineral that makes it gleam is mica.

A large slab of mica with surface ridges. A thin piece of mica can be seen flaking off in the top right area of the piece.

NPS Photo / Andrew Weiland

A very thin transparent piece of mica, crafted into an effigy of a bird's claw. A white background piece has been placed directly underneath to show the shape of the mica.

NPS Photo / Andrew Weiland

The shimmer and shine of mica likely attracted people 2,000 years ago, resulting in the material showing up often at archeological sites of the Scioto Hopewell culture. Archeologists have found large sheets of mica carved into shapes including a raptor’s talon, a human hand, and large round discs. Mound 13 at Mound City Group in Hopewell Culture National Historical Park is often referred to as the Mica Mound. In that mound, archeologists of the 1920s uncovered a large clay basin or platform completely lined with large mica sheets ranging from 6 to 16 inches in diameter, the cremated remains of four individuals rested on top of these mica sheets along with other sacred artifacts accompanying the dead.

One of the few places in the world to find large sheets of mica is in the Blue Ridge Mountain region in western North Carolina. That is over 400 miles away from Mound City Group! Mica is mined in large pits. Large chunks, called “books,” are removed and split apart into thin sheets. The material is also rather soft and is easily carved resulting in some of the detailed artifacts described above.

2,000 years ago, mica might have adorned the ceremonial clothing of the people that gathered at the earthwork complexes at Hopewell Culture National Historical Park. The shapes would catch the light and reflect the shimmer and glow of a fire. The large plates of mica may have been used as mirrors by ceremonial leaders. It was a sacred and special material to the people participating in the Scioto Hopewell culture.

In our culture we still use mica to make ourselves stand out in a crowd, the mineral can be found in paints, many make-up brands, and ground up mica adds sparkle to toothpaste and helps polish your teeth- yet another way to help us shine! Additionally, mica has a very high heat tolerance and is used to make windows for ovens and coating for electrical wires.