Formation: Forms in hydrothermal vents and some sedimentary rocks
Properties: RADIOACTIVE! As you can see from the photograph at left, pitchblende is an ore of uranium, which means that it is highly radioactive. The photograph shows a small piece of pitchblende from the collection of YourGemologistthat is reading half way across the scale, and this is set on the highest reading possible. Meaning that this specimen is giving off a tremendous amount of radiation. This is the natural source of nuclear energy, but it can be dangerous and must be handled carefully. It can make for a good classroom demonstration of radioactivity in carefully controlled environments, but should not be thought of as a fun rock to show and tell your friends about.