Iron Ore

Iron ore is a mineral block found underground. It is the most common mineral that can be used to make tools and armor. It has the appearance of discolored gold ore.

Iron ore requires a stone, iron, or diamond pickaxe to successfully mine. It must then be smelted in a furnace to obtain an iron ingot; iron ingots can be used to make medium quality tools, armor, buckets, Flint and Steel and shears, as well as a compass. A full list of craftable items can be found here.

Iron ore is often used in player traps as it can be mined and replaced in its raw form, like Gold Ore.

Natural Occurrence
Iron occurs only around from bedrock to slightly above sea level (layers 1-63). However, almost all of the iron ore will be underground. It composes approximately 1.3% of all blocks on layers 5-40, tapering off above that. On average, there are about 77 iron ores per chunk. Due to being extremely common, iron veins are frequently seen at the boundaries of any hollow space such as caves and lava lakes, but they are no more common there than in any other volume of stone.

Veins can vary in size, but the most common is 2×2×2. Iron always comes in veins of 4 to 10 unless dirt, gravel, a cave, or another ore overlapped into it. Each block in the vein which otherwise would be stone has a random chance of being iron ore instead (therefore it is good practice to check around a located ore block for more ore, as ore blocks may be only diagonally adjacent rather than face-to-face). If the vein intersects a cave or other structure, part of it may be replaced with air. Occasionally, two veins will form next to each other, making it look like a bigger vein with more than 10 ores.

Trivia

 * In third person view or when looking at Endermen, any ore held may have a reversed texture.
 * Iron ore can rarely be seen from the surface.
 * Iron, coal, gold, diamond and redstone ores all have the same texture, with different colors of the spots being the only way to separate them. However, emerald ore, Nether quartz ore and lapis lazuli ore have different textures.

Gallery
Eisenerz Iron (Ore)/es Fer (minerai) 철 원석 IJzer (erts) Ruda żelaza pt-br:Iron (Ore)/ptbr Железо (руда) 铁矿石