Pitchblende is a heavy, dark mineral that contains uranium, the radioactive element used in nuclear power and atomic weapons.

For centuries, miners considered pitchblende worthless ore that just happened to show up near more valuable metals like silver. But in 1898, scientists Marie and Pierre Curie made a revolutionary discovery while studying pitchblende: they found two new radioactive elements hidden inside it, which they named polonium and radium. Their work helped unlock the secrets of radioactivity and earned Marie Curie two Nobel Prizes.

Today, pitchblende matters because it's one of the main sources of uranium. Scientists mine and process it to extract uranium for generating electricity in nuclear power plants. The uranium inside pitchblende is naturally radioactive, meaning it gives off energy as its atoms slowly break apart over thousands of years. This same property that makes uranium useful also makes pitchblende dangerous to handle without proper protection, since the radiation it releases can harm living things.