The Ring of the Inferno is one of the Legendary Rings of Power created by the Valar. This one was meant to be used for good, but was tainted when Nahir snatched it from Valinor.
The Ring of the Inferno was forged by Aule in Valinor during the First Age. He would use it to help him with his greatest creations, things such as new ores and magical weapons. But this changed when Melkor fled Valinor, taking many Maiar with him. One of these Maiar, Nahir, was smart enough to snatch the ring from the forges before escaping.
The Ring of the Inferno is gold, but encrusted with blood-red rubies. It has an aura of intense heat, and its touch could melt iron.
The Ring of the Inferno greatly enhances the wearer's smithing skill to that of Aule. Anyone would have the skill to forge their own Silmarils, if they knew what the Silmarils were made of. With Nahir's upgrades, it turns the wearer's eyes flame orange, and allows them to harness the power of fire. They could throw fireballs, swim through lava, and breathe smoke without being harmed. The downside is that the wearer would not be able to stand cold climates like Forodwaith, which would kill them.