How are Metals Formed?

Everything on earth is made up of a combination of building blocks called the chemical elements. 
There are 93 different elements in nature, and most of these are metals. 

Most metals can combine with other chemical elements to form compounds.
These compounds are called minerals when they are found in rocks and soil.
Most minerals grow in liquids, sometimes forming where molten rocks from beneath the earth's crust cool and harden. These metal-containing rocks are called ores.
The large iron ore deposits in Kiruna, in northern Sweden, were formed in this way.
As the molten rocks cool, a mixture of minerals, gas and hot water forces its way into cracks in the rocks. This mixture also cools and hardens to form thin lines that are rich in metallic minerals like lead, copper and zinc.
Some metal elements do not combine easily with other elements.
These metals, like gold, silver and platinum, occur naturally in the earth's crust as small grains, or as larger lumps of metal.
Falling rain and rivers wash these metals out of rocks on the earth's surface.
The heavier metals drop in one area and form placer deposits.
When these deposits occur on river beds, special dredgers sort the metals from gravel deposits.
 Powerful water jets are used to break up dry placer deposits.
The gravel is washed and separated from the metal ore.