Mineral Resources

Where Minerals Are Found  The Earth’s crust is made up of mostly common rock forming minerals combined in various types of rock.  Less common and rare minerals are not evenly spread throughout the crust.

The Uses of Minerals  Minerals are the sources of metals, gemstones, and other materials used make many products.

Gemstones  Gemstones are highly prized minerals because they are rare, beautiful and durable.  Usually a gemstone is a hard, colorful mineral that has a brilliant or glassy luster.  Once a gemstone is cut and polished, it is called a gem.  Uses: jewelry, decoration, mechanical parts

Metals  Some minerals are the sources of metals such as aluminum, iron, copper and silver.  Metals can be stretched into wire, flattened into sheets, molded and hammered without breaking.  Think of all the things made of metal in your life.  All these began as minerals inside the Earth’s crust.

Other Uses of Minerals  People use materials from minerals in food, medicines, fertilizers, and building materials.

Ores  Ore is a rock that contains a metal or economically useful mineral that can be mined at a profit (Give example).  Not all metals occur in pure form.  Iron which is used in everything from frying pans to ships, is obtained from its ore hematite. Magnetite is another mineral that contains iron.

Prospecting  Searching for an ore deposit.  Some ores can be found near certain features on the Earth’s surface.  Test plants growing in an area for the presence of certain chemicals.  Geologist also set off explosions below ground to create shock waves. The echoes of these shock waves can be used to map the size, shape and location of the ore deposit.

Mining  Geologist help determine how the ore should be mined from the ground.  There are 3 types of mines: Strip Mines Open Pit Mines Shaft Mines

Strip Mine (Surface Mining) Strip Mining: Soil or dirt is moved to expose ore.

Open-pit Mine (Surface Mining) Open-pit Mining:  Miners dig an open pit mine to remove ore deposits that start at the surface and may extend down deep into the Earth. Some open-pit mines are a kilometer wide and nearly as deep.

Shaft Mining Shaft Mining: Is used for deposits that occur in veins. Shaft mines can consist of a network of shafts that follow the ore.

Harmful Effects of Mining  Strip mining and pit mining leave scars on the land.  Waste materials from mining can pollute rivers (Examples: acid mine runoff and sediment in streams).  Often in strip mining the soil is replaced and vegetation planted. This called reclamation.

Smelting  Ores must be processed before the metals they contain can be useful.  During smelting, a substance is melted to separate it from any unwanted materials that may remain.  So smelting is necessary to remove the metal from the ore.

Smelting continued…  After smelting the iron has to be further processed to remove impurities from the iron.  The result is steel, which is much stronger.

Steel  Steel is stronger than iron.  Steel is an alloy: a solid mixture of two or more metals.  Steelmakers mix iron with other elements to create alloys with special properties.  Stronger steel: mix with manganese and carbon  Rust resistant steel: mix with chromium and nickel