Step 9: Adding a Smelting Recipe!
Now, also in the load() method add:
GameRegistry.addSmelting(yourFirstOre.blockID, new ItemStack(yourFirstItem), 0.1F);
The first parameter is the input, in this case the ore block we added above, the second parameter is a new ItemStack containing whatever you want the furnace to smelt out, in this case it's the item we just created. The last parameter is the amount of experience the furnace recipe will provide (gold is 1.0F, wood is 0.15F). That's it! You now have an ore which you can smelt into an ingot (or other item). This will be helpful for the next tutorial, where we create a new tool set.