“There’s gold in them there hills!” The famous Gold Rush exclamation may also be true for copper, nickel, cobalt, or rare earths, minerals that in the right hands can be as valuable as gold.

In the Gold Rush days, miners used pickaxes, shovels, and pans to hunt for the glittery substance. Today, mining companies spend billions searching for new mineral deposits, using advanced technological methods such as geological mapping, drilling, satellite imaging, and geophysical surveys. These methods can be extremely effective, but they are also expensive, time-consuming, and can be environmentally disruptive.