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Minerals are all around us
Chapter 2 section 1
CHAPTER
KEY CONCEPT
NEW CHAPTER
CHAPTER
HOME
Minerals
VOCABULARY
the BIG idea
Minerals are basic building blocks of Earth.
2.1 Minerals are all around us.
2.2 A mineral is identified by its properties.
2.3 Minerals are valuable resources.
CHAPTER OUTLINE
CHAPTER RESOURCES
Minerals are all around us
Minerals have four characteristics:
• A mineral is a substance that:
1. Forms in nature
2. Is a solid
3. Has a definite chemical makeup
4. Has a crystal structure
2.1
CHAPTER HOME
KEY CONCEPT
Minerals are all around us.
VOCABULARY
mineral
formed in
nature
solid
element
crystal
A mineral has
four
characteristics.
crystal
structure
cubic
CHAPTER
RESOURCES
SECTION
OUTLINE
2.1
CHAPTER HOME
KEY CONCEPT
Minerals are all around us.
VOCABULARY
mineral
formed in
nature
solid
chlorine
element
crystal
A mineral has
four
characteristics.
definite
chemical
makeup
crystal
structure
sodium
halite
VISUALIZATION
CLASSZONE.COM
Explore an animation of crystal
growth.
CHAPTER
RESOURCES
SECTION
OUTLINE
Minerals are different from rocks
• A mineral must have the four characteristics.
• A rock has only two, it is a solid and it forms
naturally.
http://www.youtube.com/watch?v=mkrm5G
UGJ3U&feature=related
1. Formed in nature
• Minerals formed by natural processes.
• The mineral halite (table salt), forms when
water evaporates in a hot, shallow part of the
ocean, leaving behind the salt it contained.
• Many types of minerals, including the ones in
granite, develop when molten rocks cool.
• Talc, a mineral that can be used to make baby
powder, forms deep in Earth as high pressure
and temperature cause changes in solid rock.
2. Minerals are solid
• A mineral is a solid, it has a definite volume
and a rigid shape.
• A liquid or gas is not a mineral.
3. A mineral has a definite
chemical makeup
• It consists of specific combination of
elements.
• An element is a substance that contains only
one type of atoms.
4. A mineral has a crystal structure
• A crystal is a solid in which the atoms are
arranged in an orderly, repeating threedimensional pattern.
Diamond and Graphite
• Both consists of one element -Carbon.
• The arrangement of the carbon atoms are not
the same, so they have different crystal
structure and different properties.
• Diamond is extremely hard and sparkles,
graphite is soft and dull.
Minerals are grouped according to
composition
• Scientist classify minerals into groups based
on their chemical makeups.
• The most common group is the silicates. All
the minerals in this group contain silicon and
oxygen joint together.
• Only 30 minerals make up most rocks in the
crust. That is why they are called rock-forming
minerals.
• Silicates, make up 90% of rocks on Earth’s
crust. They are the most common rockforming minerals.
• Second most common group of rock-forming
minerals is the carbonates.
• All minerals in this group contain carbon and
oxygen joined together.
A mineral is identified by its
properties
Section 2
Minerals appearance help identify
it :
• To identify a mineral we need to observe its
properties.
• Many minerals occur in more than one color,
that is why it is not reliable clue, and we need
to examine other properties.
Different forms of quartz
• Streak is the color of the powder left behind
when the mineral is scraped across a surface.
http://www.youtube.com/watch?v=VnM8ebB06MU
• A mineral can vary in color, but it always has
the same streak.
Luster
The way in which light reflects from its surface
Metallic luster (like a metal)
non- metallic luster (not like a metal)
The way a mineral breaks help identify
it:
• Cleavage is the tendency of a mineral to break
flat smooth surface.
http://www.youtube.com/watch?v=bYiT2qg
D8zQ&feature=related
• Fracture, is the tendency of a mineral to break
into irregular piece.
A mineral’s density and hardness
help identify it :
• Density is the amount of mass in a given
volume.
• We can tell the minerals apart by their density
– Gold is more dense than fool’s gold
Gold
Pyrite (fool’s gold)
Hardness
• The resistance to being scratched.
The stronger the
bonds, the harder the
mineral.
http://www.youtube.com/watch?v=ju8Gkv14P74
Some minerals have special
properties
• Some minerals in the carbonate group, such
as calcite reacts with acid.
http://www.youtube.com/watch?v=OXxyrcPdmpA&feature=related
Some minerals have Fluorescence
property
• Theses minerals know as Fluorescent
minerals.
http://www.youtube.com/watch?v=sQwGZLi4JYE
Some minerals have magnetism
property
• Minerals have magnetic power.
1. Name one mineral on
the Mohs scale that is
softer than fluorite.
2. What is the hardness
of topaz on the Mohs
scale?
3. Is topaz harder or
softer than a steel file?
4. Explain why you could not
use a steel file to tell the
difference between a
sample of topaz and a
sample of quartz.
homework
• Review Questions 2.2
1, 2,3,4
Mineral are valuable resources.
Section 3
Minerals have many uses in industry:
• Metals for cars and airplanes.
• Quartz and feldspar for glass
• Fluorite and calcite for toothpaste
• Talc in powder
Minerals have many uses in arts:
• Birthstone, Gemstones.
• Gemstones are used in jewelry, as are
platinum and gold.
• Diamonds are used as abrasives, as a drill tip.
• Copper is used in wires and electronics.
Minerals form in several ways:
1.
2.
3.
4.
5.
Water evaporates.
Hot water cools.
Molten rocks cools
Heat and pressure cause change
Organisms produce minerals
1. Water evaporates
• Water has many minerals dissolved in it, when
the water evaporates, the minerals remain.
• Ex: table salt, Gypsum
Salt, and gypsum form
as water evaporates
2. Hot water cools
• Hot water within Earth’s crust can dissolve
minerals and move them to other places
between the cracks of the rocks. When hot
water cools, the mineral turns to solid.
• Gold is formed when
Hot water cools.
3. Molten rocks cools:
• Many minerals grow from Magma.
Magma –( molten rock inside Earth)
• Minerals also formed as Lava cools.
Lava – (molten rock on Earth’s surface)
• Ex: Quartz
Lava is melted rock that erupts onto Earth's
surface.
Granite is a type of rock that forms from
Rhyolite rocks contain minerals that are
magma. It contains the minerals quartz
similar to granite, but the crystal size is
(clear), plagioclase feldspar (shiny white),
much smaller.
potassium feldspar (pink), and other
minerals.
Quartz formed when molten rock cools
4. Heat and pressure:
• Heat and pressure within Earth can cause new
minerals to form.
• Ex: the element Carbon (C ) is present in some
rocks, at high Temperature it will change to
graphite, that is used in pencil.
5.Organism produce minerals:
• A few minerals are produced by living
organisms.
• Ocean animals like oysters and clams produce
calcite to form their shells.
• Our body produce a mineral
In our bones and teeth- apatite.
Many minerals are mined
• Some minerals are found near Earth’s surface.
Others lie deep underground.
• Minerals to be mined, need to be present in
large amount in a rock.
• Rocks contain enough of a mineral to be
mined for a profit are called Ores.
Types of mining
Minerals near the Earth’s surface
1. Surface mining.
Minerals lay underground
2. Deep mining
Surface mining
Open-pit mining
panning
Strip mining
• Panning: a miner uses a pan to wash away
unwanted minerals that are less dense.
Strip mining: Miners strip away trees, plants, soil
and unwanted rocks . They use special
machines to dig.
• Open pit mining: Miners use explosives to
break the underlying rock and recover the ore.
like
Copper and iron
http://www.youtube.com/watch?v=ukPyhbWbnSI&feature=related
Deep mining
• A method used when the ore lies far below
Earth’s surface.
http://www.youtube.com/watch?v=9Bw
G4Poy4PE&feature=player_embedded
• Chilean miners
• Tour a coal mine
http://www.youtube.com/watch?v=kZAM6U
TWWUM&feature=fvsr
http://www.youtube.com/watch?v=BkjrbCi7Sc&feature=fvw