The benefits of gamma rays are most clearly seen in the medical field, where they are used to treat cancers and tumors. A technology called the gamma ray knife uses concentrated gamma ray beams to target and destroy cancer cells.
Gamma rays are also used in PET scans and bone scans to detect malignancies. Medical personnel use an isotope of cobalt called cobalt 60 as a source of these gamma rays. Gamma rays are also used in autoclaves to sterilize medical instruments.
These high-energy rays are also used in the food industry to irradiate food. Irradiation kills bacteria and pathogens and keeps fruit and vegetables fresher longer by interrupting the ripening or sprouting process.
Gamma rays are also used to inspect castings for cracks and imperfections that can't be seen with the human eye. The jewelry industry also makes use of gamma rays. The application of gamma rays to white topaz changes it to blue topaz.
Gamma rays are common in outer space and are created by very hot objects, such as neutron stars and the areas around black holes. Scientists use the gamma rays emitted from the nuclei of the elements found on planets to determine the material that comprises the planet.