Autunite is a pale yellow to greenish-yellow mineral that is a significant source of uranium. It is a widely recognized phosphate mineral that is composed of calcium, uranium, and hydrogen phosphate. Although the word is specific to this mineral, there are several synonyms for autunite that can be used in scientific literature or general discussions. These synonyms include uramphite, hydrogenautunite, and calcioautunite. They are all basically different forms of autunite that share similar physical properties and elements. Regardless of which term is used, they refer to a mineral that is an important source of uranium and has been used in the production of nuclear energy.