Overview:
Students review the differences between rocks and minerals and categorize the ranks of coal. They also complete a map activity identifying countries and states where large deposits of coal are found.
Objectives:
Students will:
review the characteristics of rocks and minerals,
examine samples of coal and hypothesize whether the samples are rocks or minerals,
identify the locations of the largest coal reserves in the United States and around the world, and
understand the role that coal plays in the U.S. economy.
Discussion Questions:
What is the difference between a rock and a mineral?
Is coal a rock or a mineral?
Where is coal found?
Procedure:
Begin by explaining or reviewing the differences between rocks and minerals. You may want to write this information on the blackboard or display it on the overhead projector and have students copy it into their notebook. Explain that minerals are inorganic (nonliving) substances found in nature that are made of single elements or compounds. There are many types of minerals. Students may even recognize a few, such as copper, gold, silver, diamond, topaz, and quartz. A rock, on the other hand, is a combination of two or more types of minerals fused together. Rocks may sometimes include organic materials such as microscopic remains of plants or animals. Both rocks and minerals are essential components of our planet.
Rocks are classified according to how they form. There are three types of rock: igneous, sedimentary, and metamorphic. Igneous rock forms when magma, molten rock material within the earth, forces its way to the surface and cools. Sedimentary rock forms from mineral fragments deposited by wind, water, or glaciers. Metamorphic rock is rock whose minerals and texture have been changed by high temperatures, water, and pressure.
No rock's life is set in stone. One type of rock can change into another when erosion, heat, or pressure (or a combination of all three) break down the rock and transform it. This transformation is called the rock cycle. It can take thousands, even millions, of years for one type of rock to change into another. Through the forces of nature, the earth's landscape is constantly changing.
Pass an unidentified sample of anthracite coal around the classroom and ask students to guess whether the object is a rock or a mineral. Explain that the object is a rock, but see if students can guess what kind of rock it is. When students have finished guessing, explain that anthracite is a type of coal that is formed by metamorphism. Most other types of coal are classified as sedimentary rock. Reproduce the following chart on the blackboard or overhead projector. Pass around the other samples of coal as you review the four types of coal.
Type of Coal
Appearance
Texture
Rock or Mineral Classification
Carbon Content
Peat
Dark brown to black, with many visible plant fragments
Soft; breaks unevenly when dry
Sedimentary rock
Low
Lignite
Brown, with some visible plant material
Crumbly
Sedimentary rock
Medium
Bituminous
Black; dirty to handle
Hard and brittle
Sedimentary rock
High
Anthracite
Glassy black
Uneven surfaces
Metamorphic rock
Extremely high
Explain to students that the carbon content in coal makes it burn and produce heat used to generate energy in power plants. Coal is important because of its abundance and its use in producing energy. Ask students if they know where coal can be found.
Distribute two blank outline maps: one of the world and another of the United States. Have students create a color-coded legend for the world map, identifying, in order, eight countries with the largest coal reserves. Using their own legend, have them color in the following countries according to their rank in recoverable coal reserves. Provide the information in descending order so that students are surprised to find that the United States has the largest recoverable coal reserve in the world.
8. Ukraine
7. South Africa
6. Germany
5. Australia
4. India
3. China
2. Russia
1. United States
Ask the students if they are surprised to find that the United States has more coal than any other country in the world. Ask them if they know where in the United States coal is found.
Name the 37 states that have coal deposits. As you do, have students identify them on the map, then color or shade them in. Begin with the more obvious coal mining states and continue through all 37 coal-producing states. (The following are states without coal deposits: Connecticut, Maine, New Hampshire, Vermont, Hawaii, New Jersey, Rhode Island, Delaware, South Carolina, Florida, Wisconsin, Minnesota, and Massachusetts.)
Ask students whether they are surprised to find out how many states have coal deposits. Tell them that one-eighth of the land area of the United States lies atop coal beds.
As a class, discuss the role that coal plays in the economy of the United States. Review with students that coal is a plentiful, inexpensive, and reliable source of energy. How do these attributes affect the economy of the United States and the lives of Americans?
Assessment:
Have students write a newspaper article or a television news report about coal. Make sure they include information about where coal can be found, what types of coal there are, what characteristics coal has, and how it is used.
Extension:
This same type of mapping activity can be done with other rocks or minerals, such as gold, silver, copper, granite, quartz, marble, or slate. In any case, the study should culminate in a discussion about the importance of the rock or mineral to humans and where it can be found.
Differentiation:
Reproduce and distribute the chart to students with impaired vision who might have difficulty copying it from the blackboard or overhead projector.
