Vulcanite is a new ore added with this mod that aims to improve your experience in the Nether. The armor has more durability against fire and the tools are enhanced as well. And it all starts with the Vulcanite ore.
The tools and armor are crafted differently than traditional tools and armor. You need to start with a base iron tool or armor piece and use an anvil with Vulcanite nuggets to get the desired item. There’s a handy guide found here for detailed information on how things are crafted and used with this mod.
Then you can use these new tools for faster block breaking with a pickaxe, axe or shovel. They can even smelt blocks as you mine them!
And fire immune mobs are more vulnerable to these tools as well.
You can even craft flint and vulcanite that can ignite mobs and TNT faster as well.