More silver facts. 1  While aluminum is the most common metal found in the Earth's crust, the most common metal found on Earth is iron, mostly because it makes up such a large part of the Earth's core.2  More iron facts. 3  Copper is a good conductor of electricity and is often used for making wires.ore silver facts. 1  While aluminum is the most common metal found in the Earth's crust, the most common metal found on Earth is iron, mostly because it makes up such a large part of the Earth's core.