Transcript Ch 13: Minerals

Chapter 13
Section 1 What Is a Mineral?
• A mineral is a naturally formed, inorganic solid
that has a definite crystalline structure.
How do we know if something is a mineral?
• Does it have a crystalline structure?
• Is it a nonliving material?
• Is it a solid?
• Is it formed in nature?
Chapter 13
Section 1 What Is a Mineral?
Elements are pure substances that cannot be
separated or broken down into simpler substances
by chemical means.
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.
Crystal a solid whose atoms, ions, or molecules
are arranged in a definite pattern
Chapter 13
Section 1 What Is a Mineral?
A mineral that is composed of only one element is a
Native Element and two examples are Gold and
Silver.
Silicate minerals are minerals that contain a
combination of silicon, oxygen, and one or more
metals.
Chapter 13
Section 1 What Is a Mineral?
• 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
Sulfates
Sulfides
Oxides
Chapter 13
Section 2 Identifying Minerals
Identifying Minerals
• Color - usually not the best way to identify a
mineral.
• luster - the way a mineral reflects light is called
• Metallic
• Submetallic
• Nonmetallic
Chapter 13
Section 2 Identifying Minerals
• Streak - The color of a mineral in powdered form
• Not always the same as minerals color
• Use streak plate
Chapter 13
Section 2 Identifying Minerals
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
Mohs hardness scale.
Chapter 13
Section 2 Identifying Minerals
• 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
Chapter 13
Break
Section 3 The Formation, Mining, and
Use of Minerals
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Formation of Minerals
• 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
• Metamorphic Rocks When changes in pressure,
temperature, or chemical makeup alter a rock,
metamorphism takes place.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
• 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
• 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
• 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
• 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
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
Mining
• Ore - a mineral deposit large enough and pure
enough to be mined for profit.
Chapter 13
Section 3 The Formation, Mining, and
Use of Minerals
• 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
• 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
•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
• 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
• Nonmetallic Minerals are good
insulators of electricity. They have
uses that range from glass-making 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
• Gemstones are highly valued for their beauty and
rarity, than for their usefulness.