Pyrite Sun

Whether you call them Pyrite Suns or Pyrite Dollars, these interesting mineral formations look like mineralized sand dollars! A unique crystal formation, the Pyrite actually formed as a concretion approximately 300 million years ago. As the Pyrite was compressed between layers of shale, it was unable to grow vertically / outward, and was forced to grow in a lateral or radial pattern. This created the fun disc shape these specimens from Sparta, Illinois are known for.