When you pick up a stone, there is a high chance that the stone you picked contains metals, such as aluminium and potassium. A regular stone can even contain small amounts of gold or uranium.

However, extracting these metals from small stones is often not cost-effective, as the amount of metal contained in the stone is too small.

If a rock contains enough metal to make its extraction and refining economically feasible, the rock is considered to be an ore. The concentration of metal required to make extraction profitably varies greatly between different metals.

For example, over half of the weight of iron ore has to contain iron to make extraction profitable, whereas mining gold is profitable even when a ton of ore contains only a few grams of gold.

Ores are mined, extracted, and refined into metals. The production of metals is an economically important activity. We all use a large amount of different metals in our daily lives. 

Steel, which is a refined form of iron, is the most common everyday metal. It can be found everywhere in our environment, from buildings and vehicles to domestic appliances and cutlery.