Uraninite

Uraninite is the most important radioactive mineral and was once thought to be worthless. When the discovery of its useful uranium content was unveiled, it became extremely significant. It is the most common and widespread uranium mineral, making it the best-known uranium ore. Many collectors refrain from collecting uranium minerals such as Uraninite because of their hazards and fragility. Uranium minerals should be kept out of light, preferably in a tight container, and unnecessary handling should be avoided. Hands should be washed after contact with any uranium mineral, and these minerals should not be stored in a room where one eats or sleeps on a regular basis.