AIDE Earth Science Key Points
Chapter 7 "Minerals"
Lesson
1 "Minerals"
Key Vocabulary Terms
- mineral - element or compound
found in the earth.
Key Concepts
- A mineral is a solid, formed
naturally in the earth, having the same chemical makeup throughout, not
made of living things, and having a definite atomic pattern.
- Some common minerals are gold,
quartz, diamond, carbon, feldspar, mica, calcite, dolomite, halite, or gypsum.
- Geologists are able to find
minerals because they look for clues on the earth's surface. these might
include the kinds of rocks or plants in an area. Sometimes geologists test
running water for traces of minerals.
- Minerals are taken out of
the earth by being stripped off the earth's surface or dug out of open pits.
People reach minerals far underground by digging long shafts.
- Minerals are purified either
by melting them or by using chemicals to break them apart.
Did you learn these Objectives?
- Are you able to explain what
a mineral is?
- Can you name some common minerals.
- Can you explain how minerals
are located and mined?
Lesson 2 "Properties Used to Identify
Minerals"
Key Vocabulary Terms
- luster - how a mineral reflects
light.
- streak - color of the mark
a mineral makes on a white tile.
- hardness - ability of a mineral
to resist being scratched.
Key Concepts
- Different colors of the same
mineral appear because tiny amounts of different minerals, called impurities,
can give samples of the same mineral different colors.
- silver has a white or gray
color and a metallic luster.
- You determine a mineral's
streak by rubbing a soft mineral across a white porcelain tile. The color
of the mark it leaves is the mineral's streak.
- A mineral with a higher number
is harder than a mineral with a lower number a softer mineral, like quartz,
will not scratch a harder mineral like topaz.
- A mineral that is between
5 and 6 an Moh's hardness scale would be scratched by steel but does not
scratch glass.
Did you learn these Objectives?
- Can you identify four properties
of minerals?
- Can you assess color as a
wy to identify minerals?
- Are you able to define luster?
- Can you describe a streak
test?
- Are you able to explain how
to test the hardness of a mineral?
Investigation
7-1 "Observing Color, Streak, and hardness." (Optional, must complete
16 total investigations)
Key Concepts
- In this investigation, you
will describe the color streak, and hardness of known mineral samples.
Lesson
3 "Other Physical Properties of Minerals"
Key Vocabulary Terms
- crystal - basic shape that
a mineral tends to take.
- cleavage - ability to split
along a flat surface
- Fracture - tendency to break
with jagged edges.
- specific gravity - mineral's
weight compared to the weight of water.
Key Concepts
- The arrangement of atoms determine
a crystal's shape.
- Cleavage is a mineral's tendency
to break along flat surfaces, a mineral that fractures leaves a jagged edge.
- Specific gravity measures
the density or a mineral's weight compared to weight of the same volume
of water.
- A mine aral 10 times heavier
than water would have a specific gravity of 10.
- The specific gravity of water
is 1.
Did you learn these Objectives?
- Are you able to explain what
a crystal is?
- Can you recognize how minerals
break?
- Can you measure the specific
gravity of mineral samples?
Investigation
7-2"Finding Specific Gravity" (Optional, must complete 16 total
investigations)
Key Concepts
- In this investigation, you
will find the specific gravity of unknown mineral samples.
Lesson
4 "Common Uses of Minerals"
Key Concepts
- A diamond is used to make
drill tips because it is the hardest known mineral.
- Gold and copper are useful
in computer parts because they conduct electricity.
- Glass is made from the mineral
quartz.
- Two types of minerals that
make gems are diamond, ruby.
- There are many minerals we
use everyday and they may include: graphite (pencil lead), iron (cars),
quartz (glass), bauxite (soft-drink cans) gypsum (wallboard)
Did you learn these Objectives?
- Can you realate the usefulness
of minerals to their properties?
- Are you able to identify minerals
that are precious metals or gems?
Chapter Summary and Review
See page 174-175
Chapter 7 Review answers are
1.fracture
2.crystal
3.hardness
4.cleavage
5.mineral
6.streak
7.luster
8.specific
gravity
9.C
10.B
11.D
12.B
13.A
14.D
15.cinnabar
16.galena
17.Minerals
can be skimmed from the earth's surface in a strip mine or dug deep out of
the ground by means of long shafts.
18.Weith
the sample in the air; then weigh it submerged in water. subtract it weight
in water from its weight in air. Divide the weight in air by the difference
you calculated in the previous step. this number is the sample's specific
gravity.
19.the
samples are probably different varieties of the same mineral.
20.By
testing the hardness and specific gravity of each mineral, you could determine
which was quartz.