Post-reform radiate

The post-reform radiate (this is a later name given by numismatists; the contemporary Latin or Greek name, like many Roman coins of this time, is unknown), was a Roman coin first issued by Diocletian during his currency reforms of AD 293–310.[1] The radiate looked very similar to the Antoninianus (pre-reform radiate), with a radiate crown, similar to the one worn by the Roman deity, Sol Invictus. It is different from the Antoninianus because of the absence of the "XXI" that existed on pre-reform radiates, a symbol believed to have indicated a consistence of 20 parts bronze to 1 part silver. The post-reform radiate had little or no silver content. The weight can vary between 2.23[2] and 3.44 grams.[3]

There also exists radiates of Maximian, Constantius I, and Galerius, Diocletian's co-rulers, in the same style.