Planet Earth – Minerals and Rocks

A mineral is a naturally occurring, solid substance.

A rock is a combination of one or more minerals.  Rocks created by volcanic activity are known as igneous.  Rocks made from compressed layers of sediment are sedimentary, and rocks formed when changes in temperature or pressure cause one type of rock to change into another are called metamorphic.

Rock-forming minerals are classified according to the elements they are from.  Elements are the basic building blocks of all matter.  Just eight elements (oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium) make up nearly 99 percent of Earth’s crust.  These and other elements combine to form the minerals that in turn combine to create rocks.

An ore is a rock containing valuable mineral deposits that are economically profitable to extract.

Bauxite ore is the main source of aluminum.  Aluminum conducts electricity well, is lightweight, and resists corrosion.  Aluminum is the second most widely used metal after iron.  Aluminum is the most abundant metal on Earth.  Aluminum is almost never found in its native state.  Instead, it is found combined with other minerals in various ores.  Other important metal ores include sphalerite (zinc), nickeline (nickel), cassiterite (tin), galena (lead), and cinnabar (mercury).

Bauxite was named after Les Beaux-de Provence in France where it was first discovered in 1821.

Aluminum has many uses, including making power lines, aircraft, beverage cans, cooking utensils and more.  Aluminum compounds (mixtures) are used in the production of glass and ceramics, and in the manufacture of jet fuel, paints, and antiperspirants.