How did Diocletian reform Roman coinage?

Diocletian implemented a comprehensive monetary reform between approximately 286 and 296 CE to address the instability of prices and restore a sound financial system. His reforms included the following measures:12

• Restoration of Precious Metals: He introduced new gold aurei struck at 60 to the pound of gold and new silver coins of high purity, struck at the revised Neronian weight of 96 to the pound of silver.12
• Bronze and Small Coinage: He created new, larger, and more valuable copper coins to replace the debased double denarii of previous reigns, alongside the circulation of small coins to facilitate daily financial exchanges.12
• Minting Infrastructure: To support these changes, he decentralized minting and increased the number of imperial mints from 8 to 15, spanning from Londinium to Alexandria.12
• Standardization: The new coinage featured fixed designs, with silver and copper types closely controlled—most notably the "Genius Populi Romani" type for copper coins.12

These efforts were part of a broader attempt to stave off financial crises, which also included the issuance of the Edictum de Maximis Pretiis in 301 CE to fix wages and maximum prices.1