Iron Ore is an ore in Survival 303.
Iron Ore is the most common ore found in the game, and can be mined with any pickaxe. It is found in more than one vein on Spire, Rockma, Mainland, Plateau, and Magma. However, Flax only has one vein of iron ore. Mainland, Plateau, and some veins on Spire require a light source to get to, while Rockma, Flax, Magma, and some veins on Spire do not require any light source to get to.
Iron Ore alone can not be crafted into tools or armor, it must be refined. To refine the iron, place Iron Ore near any source of fire. If you want, you can even refine iron while it's on the vein, however, you'll still need to use a pickaxe to collect it. When refined, it will become Refined Iron, and can be crafted into useful tools and items.