CHAPTER
13
Mineral Resources
and Mining
Mining for . . . Cell Phones?
• Large reserves of the metal tantalum are found in the
Democratic Republic of the Congo, in Africa.
• Tantalum jumped in value in the 1990s as high-tech
devices that need tantalum, such as cell phones,
became common.
• There is international concern regarding the role
tantalum mining has played in the extended conflict
in the Congo.
Talk About It Is it important to think about the
sources of the minerals we use?
Lesson 13.1 Minerals and Rocks
Amethyst
Over 4000 minerals have been identified, but only
1% of these are common in Earth’s crust.
Lesson 13.1 Minerals and Rocks
What Are Minerals?
• Occur in nature
• Chemically inorganic
• Solids
• Have orderly crystalline
structures
• Have definite chemical
compositions
Pyrite (Fool’s Gold)
Lesson 13.1 Minerals and Rocks
Properties of Minerals
Property
• Color
• Streak
• Luster
• Crystal
• Hardness
• Cleavage
• Fracture
• Density
Description
A few minerals can be identified by their color. But color varies in
most minerals depending on how they form.
The streak of a mineral is the color of its powder. Although
mineral color may vary, streak color does not.
How light is reflected off a mineral’s surface is called luster. It may
be described as glassy, earthy, silky, metallic, etc.
A mineral can be identified by the particular arrangement of its
atoms.
Mohs scale ranks mineral hardness 1–10.
1 = talc, which can be scratched by a fingernail.
10 = diamond, which can scratch all known common minerals.
A mineral that splits easily along a flat surface and forms a new
“face” is said to have cleavage.
Minerals that break irregularly, rather than leaving a flat surface,
have fracture, not cleavage.
Each mineral has a characteristic density—mass per unit volume.
Lesson 13.1 Minerals and Rocks
Mineral Formation
• Minerals can form in four ways:
• Crystallization from
magma or lava
• Precipitation
• Pressure and temperature
• Production by organisms
Salt basins of the Sierra Nevada
The Miwok people filled these basins with
water from a salt spring and let it
evaporate, to form salt for trading.
Coral
Mineral formed by living things
Lesson 13.1 Minerals and Rocks
Mineral Classes
• Minerals are classified based on their elements or compounds.
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decompressor
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Lesson 13.1 Minerals and Rocks
Rocks
• Naturally occurring solids
made up of minerals and
mineral-like materials
• Three types: igneous,
sedimentary, metamorphic
• The rock cycle slowly
changes rocks from one
type to another through
heating, melting, cooling,
weathering, and erosion.
Lesson 13.1 Minerals and Rocks
Types of Rocks
• Igneous: Form when magma cools and solidifies; can be
intrusive or extrusive
• Sedimentary: Form when sediments cement together or when
water evaporates and leaves behind minerals; can be clastic,
chemical, or biochemical
• Metamorphic: Form when heat or pressure changes the
crystalline structure of existing rock
Did You Know? In general, the
more slowly igneous rock cools,
the larger its crystals.
Bryce Canyon National Park
Lesson 13.2 Mining
More than a ton of waste may remain
after extracting just a few hundredths
of an ounce of gold.
Lesson 13.2 Mining
What Is Mined?
•
Ores: Groups of minerals that are mined so metal or
metals can be removed
•
Nonmetallic minerals: Minerals, including gemstones,
that as a whole have valuable properties
•
Fuels: Minerals that can be used to generate energy
Did You Know? About 100 minerals
are considered gemstones, including
diamond, topaz, and jade.
Lesson 13.2 Mining
Process of Mining and Mineral Use
From initial exploration to disposal, mining and mineral use
involve many steps.
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decompressor
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Lesson 13.2 Mining
Mining Methods
• Strip mining
• Subsurface mining
• Open pit mining
• Mountaintop removal
• Solution mining
• Placer mining
• Undersea mining
Did You Know? Some subsurface mines in
South Africa extend 4 km underground.
A strip mining operation in Wyoming
Lesson 13.2 Mining
Processing Ore
• Ores must be processed to gain access to the metals they
contain:
• Ore is crushed and ground.
• Crushed ore is separated
into metals and tailings.
• Concentrated metals
are further processed,
often by smelting.
Lesson 13.3 Mining Impacts and Regulation
There are about $314 million
worth of metals contained in
unused cell phones in the
United States alone.
Lesson 13.3 Mining Impacts and Regulation
Environmental Impacts of Mining
• Increased erosion
• Sediment and debris
clog waterways.
• Acid drainage and other
forms of water pollution
• Air pollution
• Disruption of ocean
ecosystems (undersea
mining)
Mine Remediation Mitigation of damage
caused to the hillside by strip mining
Lesson 13.3 Mining Impacts and Regulation
Social Impacts of Mining
• Property damage caused by mountaintop removal or mine
collapse
• Although mining can bring
money and jobs to poor areas
of the world, conflicts can
arise over mineral rights.
• Mining can be hazardous to
the health of the miners.
Did You Know? Around 650 miners or former
miners died from complications related to black
lung disease in 2005.
Several damaged areas in the Northern Coeur
d’Alene Mining District, in Idaho
Lesson 13.3 Mining Impacts and Regulation
General Mining Law of 1872
• Created rules to manage mining activity, but also
promoted mining
• Public land can be claimed and leased from the
government for mining.
• Claim owners can file to
patent, or own, the land
for $5 per acre.
• Amendments are
currently being
considered
Placer mine on the Hog River, in Alaska
Lesson 13.3 Mining Impacts and Regulation
Additional Mining Regulations
• Mineral Leasing Act of 1920 governs leasing of public lands
for fossil fuel, phosphate, sodium, and sulfur mining.
• Surface Mining Control and Reclamation Act (1977) requires
that coal-mining companies restore land after mining is
complete.
An abandoned mine in
New York state, now home
to hibernating bats
Lesson 13.3 Mining Impacts and Regulation
Mine Safety
• First law, passed in 1891, established ventilation
requirements for coal mines and prohibited miners under
12.
• Today, the Federal Mine Safety
Health Act of 1977
regulates mine safety.
• In 2010, an underground
explosion in a West Virginia
mine killed 29 miners.
and
Lesson 13.3 Mining Impacts and Regulation
Responsible Mineral Use
• Minerals are nonrenewable resources.
• Reducing use, reusing, and recycling minerals can help
minimize the negative impacts of mining and address
limited supplies.
Did You Know? Extracting aluminum
ore takes 20 times more energy than
obtaining it from recycled sources.