Ore is a deposit of one or more valuable minerals. A deposit is a buildup of minerals in one place. Deposits develop naturally.

Most ore deposits are found underground. The most valuable ore deposits contain useful metals. These include copper, gold, iron, and aluminum. Such metals have many important uses. We all depend on them.

Copper is used as electrical wire. It is also often used for pipes. Gold is mostly used to create jewelry.

Iron is steel's main ingredient. Steel is a very strong building material. Iron is also used in many other things. For example, it is used in glass.

Metals are often found in particular ores. For example, aluminum is usually found in the ore called bauxite. Aluminum is used in containers, makeup and medicines.

Smelting and Electrolysis

When miners find rock containing mineral ore, they first dig the rock from the earth. This can be a huge job. Sometimes millions of tons of dirt need to be moved. The rock is then crushed. The crushing is done by giant machines.

Metal is extracted, or removed, from crushed ore in one of two major ways. The first is smelting. The second is electrolysis.

Smelting uses heat to separate the valuable metal from the rest of the ore. Some metals cannot be smelted, though. The temperature they melt at is just too high. Aluminum is one example. In these cases, electrolysis is used. Electrolysis separates metal from ore by using electricity.

Ore Genesis

Deposits of ore build up over time. They are created through something called ore genesis. Ore genesis takes millions of years.

There are three major kinds of ore genesis.

First, ore can accumulate, or build up, because of things happening deep underground. One example is volcanoes. They can bring ore up from deep in the earth.

Second, ore can accumulate underwater. This happens when seawater pours through cracks in the seafloor. Then, minerals get deposited near these openings.

Finally, ore can accumulate due to wind, water, or ice. All three move earth around. This is called erosion. Often, this causes a slow buildup of ore.

Ore can also come from space. It sometimes falls to Earth as chunks of rock. Such chunks are called meteorites. Many contain large amounts of iron ore.

Modern societies depend on metallic ore. Miners must constantly look for new ore deposits. These are becoming much harder to find. Mining companies have explored every continent. They have even explored the ocean floor.