Download Section 1 What Is a Mineral?

Chapter 13
Minerals of the Earth’s Crust
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Section 1 What Is a Mineral
Section 2 Identifying Minerals
Section 3 The Formation, Mining,
and Use of Minerals
Concept Mapping
Chapter 13
Section 1 What Is a Mineral?
Objectives
• Describe the structure of minerals.
• Describe the two major groups of minerals.
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure
• A mineral is a naturally formed, inorganic solid
that has a definite crystalline structure.
• You can tell whether an object is a mineral by
asking four questions.
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure, continued
• Is it a nonliving material?
• Is it a solid?
• Does it have a crystalline structure?
• Is it formed in nature?
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure, continued
• To understand what a crystalline structure is, you
need to know a little about the elements that make
up a mineral.
• Elements are pure substances that cannot be
separated or broken down into simpler substances
by chemical means.
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure, continued
• Atoms and Compounds Minerals may be either
elements or compounds.
• A compound is a substance made of atoms of
two or more different elements joined by chemical
bonds.
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure, continued
• A mineral that is composed of only one element is
called a native element.
• Gold and silver are examples of native elements.
Chapter 13
Section 1 What Is a Mineral?
Mineral Structure, continued
• Solid, geometric forms of minerals produced by a
repeating pattern of atoms that is present throughout the mineral are called crystals.
• A crystal’s shape is determined by the arrangement
of the atoms within the crystal.
• The arrangement of atoms in turn is determined by
the kinds of atoms that make up the mineral.
Chapter 13
Section 1 What Is a Mineral?
Two Groups of Minerals
• Minerals are divided into two groups based on their
chemical composition.
• Silicate minerals are minerals that contain a
combination of silicon, oxygen, and one or more
metals.
• Examples of silicate minerals are quartz, feldspar,
and mica.
Chapter 13
Section 1 What Is a Mineral?
Two Groups of Minerals, continued
• Nonsilicate minerals are minerals that do not
contain compounds of silicon and oxygen. There
are six main classes of nonsilicate minerals.
Native Elements
Carbonates
Halides
Oxides
Sulfates
Sulfides
Chapter 13
Section 2 Identifying Minerals
Objectives
• Identify seven ways to determine the identity
of minerals.
• Explain special properties of minerals.
Chapter 13
Section 2 Identifying Minerals
Identifying Minerals
• You can determine the identity of a mineral by
noting different properties.
• Color Minerals display a wide variety of colors,
and often the same mineral can be found in many
different colors.
• Because of this, color is usually not the best way
to identify a mineral.
Chapter 13
Section 2 Identifying Minerals
Identifying Minerals, continued
• The way a mineral reflects light is called luster.
There are three types of mineral luster:
Metallic
Submetallic
Nonmetallic
Chapter 13
Section 2 Identifying Minerals
Identifying Minerals, continued
• The color of a mineral in powdered form is called
the mineral’s streak.
• A mineral’s streak can be found by running the
mineral against a piece of unglazed porcelain
called a streak plate.
• The color of a mineral’s streak is not always the
same as the color of the mineral sample.
Chapter 13
Section 2 Identifying Minerals
Cleavage and Fracture
• Different types of minerals break in different ways.
• Cleavage is the tendency of some minerals to
break along smooth, flat surfaces.
• Fracture is the tendency of some minerals to
break unevenly along curved or irregular surfaces.
Chapter 13
Section 2 Identifying Minerals
Hardness
• A mineral’s resistance to being scratched is called
hardness.
• To determine the hardness of minerals, scientists
use Mohs hardness scale, shown on the next slide.
Chapter 13
Section 2 Identifying Minerals
Chapter 13
Section 2 Identifying Minerals
Density
• Density is the measure of how much matter is
in a given amount of space. Density is a ratio of
an object’s mass to its volume.
• Different minerals have different densities.
Chapter 13
Section 2 Identifying Minerals
Special Properties
• Some properties are particular to only a few types
of minerals.
• The properties shown on the next slide can help
you quickly identify some minerals.
Chapter 13
Section 2 Identifying Minerals
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Objectives
• Describe the environments in which minerals forms.
• Compare the two types of mining.
• Describe two ways to reduce the effects of mining.
• Describe different uses for metallic and nonmetallic
minerals.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals
• Minerals form in a variety of environments in the
Earth’s crust. Each environment has a different set
of physical and chemical conditions that determine
the minerals’ properties.
• Evaporating Salt Water When a body of salt
water dries up, minerals such as gypsum and halite
are left behind.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals, continued
• Metamorphic Rocks When changes in pressure,
temperature, or chemical makeup alter a rock,
metamorphism takes place.
• Minerals that form in metamorphic rock include
calcite, garnet, graphite, hematite, magnetite, mica,
and talc.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals, continued
• Limestones Surface water and groundwater
carry dissolved materials into lakes and seas,
where they crystallized on the bottom.
• Minerals that form in this environment include
calcite and dolomite.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals, continued
• Hot-Water Solutions Groundwater works its way
downward and is heated by magma, and then
reacts with minerals to form a hot liquid solution.
• Dissolved metals and other elements crystallize
out of the hot fluid to form new minerals, such as
gold, copper, sulfur, pyrite, and galena.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals, continued
• Pegmatites As magma rises upward from the
Earth’s crust, it can form teardrop-shaped bodies
called pegmatites.
• Many gemstones such as topaz and tourmaline,
form in pegmatites.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals, continued
• Plutons As magma rises upward through the
crust, it sometimes stops moving before it reaches
the surface and cools slowly, forming millions of
mineral crystals.
• Eventually, the entire magma body solidifies,
forming minerals such as mica, feldspar, magnetite,
and quartz.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Mining
• Many kinds of rocks and minerals must be mined
to extract the valuable elements they contain.
• Geologists use the term ore to describe a mineral
deposit large enough and pure enough to be mined
for profit.
• Rocks and minerals are removed from the ground
by one of two methods.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Mining, continued
• Surface Mining When mineral deposits are
located at or near the surface of the Earth, surfacemining methods are used to remove the minerals.
• Types of surface mines include open pits, surface
coal mines, and quarries.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Mining, continued
• Subsurface Mining methods are used when
mineral deposits are located too deep within the
Earth to be surface mined.
• Subsurface mining often requires that passageways
be dug into the Earth to reach the ore.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Responsible Mining
• Mining gives us the minerals we need, but it may
also create problems.
• Mining can destroy or disturb the habitats of plants
and animals.
• Waste products from a mine may get into water
sources, which pollutes surface water and ground
water.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Responsible Mining, continued
• One way to reduce the potential harmful effects
of mining is to return the land to its original state
after the mining is completed.
• Reclamation is the process by which land used
for mining is returned to its original state.
• Reducing our need for minerals by recycling is
another way to reduce the effects of mining.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
The Use of Minerals
• Metallic Minerals are good conductors of heat
and electricity. They can be processed for various
uses, including building aircraft, automobiles, and
communications and electronic equipment.
• Examples of useful metallic minerals include gold,
silver, and copper.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
The Use of Minerals, continued
• Nonmetallic Minerals are good insulators of
electricity. They have uses that range from glassmaking to producing computer chips.
• Calcite, one nonmetallic mineral, is a major
component of concrete, which is used in building
roads, buildings, bridges and other structures.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
The Use of Minerals, continued
• Gemstones are highly valued for their beauty and
rarity, than for their usefulness.
• Important gemstones include diamond, sapphire,
ruby, emerald, aquamarine, topaz, and tourmaline.
Chapter 13
Minerals of the Earth’s Crust
Concept Mapping
Use the terms below to complete the concept map
on the next slide.
gems
compounds
atoms
mineral
mineral ore
mining
diamonds
Chapter 13
Minerals of the Earth’s Crust
Chapter 13
Minerals of the Earth’s Crust