Radioactive minerals are naturally occurring substances that contain unstable isotopes, which emit radiation as they decay. Common examples include uraninite, thorite, and monazite. These minerals are often found in igneous and metamorphic rocks and can be mined for their valuable elements, such as uranium and thorium. The radiation emitted by radioactive minerals can be harmful to living organisms, making it essential to handle them with care. They are used in various applications, including nuclear energy production and medical treatments. Understanding the properties and risks associated with radioactive minerals is crucial for safety and environmental protection.