Firestone Ore is a valuable resource in Railcraft, used to craft various machines and tools. It can be found in the Nether, and can be difficult to locate. There are a few different ways to find Firestone Ore, and the best method will vary depending on your circumstances.
One way to find Firestone Ore is to explore the Nether. Firestone Ore can be found in veins of 1-4 blocks, and is often found near lava. It is important to be careful when exploring the Nether, as there are many dangerous mobs that can spawn.