Pyrite, or "fool's gold," catches your eye with its metallic luster and brassy hue, looking like scattered coins or rough-hewn nuggets against the gray matrix of the host rock. While its color is a bold, pale gold, the mineral reveals its true identity through its sharp, cubic formations—some edges clean and defined, others slightly worn—and its subtle greenish or black streak when dragged across a surface. Holding it, you feel its surprising weight, a density that grounds the shimmering exterior, while a close look shows off its opaque, mirror-like faces that reflect the surrounding earth in miniature. These distinctive specimens are found specifically near Sparta, Illinois, where they form as flat, disc-shaped concretions known as "pyrite suns" or "mineral dollars," nestled between layers of compacted shale and coal in the region's geological formations.
Sparta, Illinois USA