What are Indian Dollars?

Rocks and Minerals Read more from
Chapter Minerals, Metals, and Other Materials

They are six-sided, disk-shaped, twin crystals of aragonite (CaCO³), which have altered to calcite but retained their outer form. They occur in large numbers in northern Colorado, where they are known as “Indian Dollars.” In New Mexico they are called “Aztec Money” and in western Kansas they are called “Pioneer Dollars.”