Iron Ore

Iron ore is found in stone.

Where Found
Iron ore can be found deep below the surface, some 50-90 blocks into bedrock, sometimes in veins or just in single blocks. The further down a Blockhead goes, the more likely it is to encounter iron ore.

Iron ore can be crafted at a press from two black sand.

Crafting
Iron ore can be crafted into an iron ingot in a furnace.

It can also be turned into pig iron along with one crushed limestone at an electric furnace.

It is also used to upgrade a furnace to level two.