Chapter 9
Rocks and Minerals
6th Grade Science
Minerals
• ___________
- a natural, non-living solid with
Mineral
a definite chemical structure.
4,000 kinds
• Earth’s crust contains more than _________
minerals – only two dozen are common.
• Examples: diamond, quartz, emerald copper
crystals
• Minerals are made up of ______.
• Particles of _______
are arranged in a
crystals
particular repeating pattern.
Crystals
Mineral
• _______
form when minerals are made in
nature
• Each type of mineral has its own unique
chemical __________.
structure
• Differences in minerals result from the way
that particles are arranged.
• Brass – Copper + Zinc –____________because
Not a mineral
it does not occur naturally
Identifying Minerals
•
•
•
•
•
_________
hardness
_________
Streak color
____________
Shape of crystals
__________
cleavage
___________
Luster
Identifying Minerals
characteristics
• Minerals are identified by their ____________
• _______________
Moh’s hardness scale - a scale to measure
hardness of a mineral
• The range of the harness scale is from 1
Softest
Hardest
(_______)
to 10 (______)
1 / diamond is a _____
10
• Talc has a harness of __
• ________
- refers to how difficult it is to
hardness
scratch its surface
Other Mineral Characteristics
• _______
- a mineral may have different
Color
crystals depending on the kinds of materials
crystals
that make up its ______.
• The color of a mineral can be seen in its
______.
streak
• A mineral can also be identified by the ______
shape
of its crystals.
• _______
Cleavage - minerals show particular patterns
when they are broken along flat planes.
Luster
• ______
Luster - the appearance of a mineral in
reflected light.
• A mineral may appear:
Metallic
– __________
– __________
Nonmetallic
Greasy
– __________
Glassy
– __________
Waxy
– __________
Value of Minerals
rare which makes them
• Some minerals are ____
very valuable
• Some minerals are valuable because they are
______________
- scientists have tried to find
Natural Resources
ways to reuse minerals or replace them with
less expensive materials.
• Aluminum and tin can be ________
recycled
• Synthetic forms of gemstones = cubic zirconia
Assessment
• Page 249 questions 1 and 2
Rocks
• _____
- a solid, natural material made up of
rock
one or more minerals
Rock cycle
• ___________
- as time passes, rock break
down, and the minerals in them are recycled –
pattern of change
• The rock cycle takes place over millions
________ of
years.
• There are three types of rocks: __________,
sedimentary
__________,
and __________
igneous
metamorphic
Sedimentary Rock
• ______________
- made from pieces of rocks
Sedimentary rock
and minerals
layers
• Sedimentary rock forms in ________
- the
oldest rock at the bottom and the newest rock
on top.
• Sedimentary rock is like a “_________”
- past
History book
events captured in each layer.
• _____
fossils - remains of once living animals or
plants
Sedimentary Rock Continued
Sedimentary rock
• Fossils are ONLY found in _____________
• Example of sedimentary rock = ________
limestone
• Limestone is made from _________________
Shells of tiny sea animals
or from dissolved __________
that settle out
minerals
of seawater.
Igneous Rock
• __________
Igneous rock - forms from magma – molten
rock inside of the earth that cools and hardens
Earth’s surface
• Some igneous rock forms Below
______________
and is only exposed after rocks above have
worn away
• Other igneous rocks form when lava
_____ cools at
the Earth’s surface
• When lava cools fast - _______________
Fine-ground rocks form
• When lava cools slowly - _______________
Coarse-grained rock
Metamorphic Rock
Metamorphic rock - forms when heat, pressure,
• _____________
or chemical reactions change one type of rock
into another type of rock.
• Metamorphic rock is made from ___________
Sedimentary rock
Igneous rock
or _________.
• Example: ______
marble is a metamorphic rock made
limestone (sedimentary rock)
from________
Compare and Contrast
• How are the three types of rocks similar and
different?
Clues to the Past
• Scientists can tell a great deal about Earth’s
history by looking at _____.
rocks
Relative dating
• ______________
- scientists look at the layers
of sedimentary rock and learn about the
relative age of each layer and the minerals
found in it.
• Relative dating allows scientists to place past
events in ____________
Sequential order
Fossils
• ________
- can form when an organisms is
fossils
buried in soft mud or when parts of the
organisms do not rot away.
• Burrows and footprints can also be fossilized
• Many fossils were made by animals that are
now _____
extinct - helps scientists determine the
rocks age.
• __________
Peoskey Stone - a fossil of marine animals
known as corals
Assessment
• How can rocks help scientists learn about the
past?
• What are trilobites and when were they on
Earth?
Soil
soil - made of weathered rock, air, water, and
• ____
the remains of living things.
weathering
• __________
- process of breaking down rocks
through physical factors such as _____,
frost
drought
rainwater or__________________.
Changes in temperature
_________,
_______
• ________
= non-living parts of the soil
inorganic
• As rock breaks down small pieces collect on
the surface
Soil Formation
• _______
and _______
are plants that help
mosses
lichens
break down rock.
• When rocks are broken down minerals
_______are
released
• ___________
- dead or decaying matter such
Organic matter
as bacteria, fungi, animals and plants.
humus
• ______
- dark colored organic matter
formed from decayed plant and animal
Rich in nutrients needed by plants
remains- _______________________
Layers of Soil
• Soils form in _____
three layers
• _________a vertical cross section of the soil
Soil profile
and rock underneath
• ________
- first layer of soil, mixture of small
topsoil
rock pieces, humus, and other organic matter
– Most living things are found in the _______
topsoil
– Loose _____________
Organic matter often covers the topsoil
– Rainwater carries minerals from the topsoil to the
2nd layer of soil.
Subsoil / Parent Rock Layers
subsoil
• _______
- less organic matter than topsoil,
lighter in color.
mineral
• _________
penetrate the subsoil through
rainwater and accumulate
Parent rock - third layer, very little organic
• _________
matter found in this layer
Kinds of Soils
Clay soils
• ________
- fine grained and hold water –
these soils can become waterlogged
• _________
- medium sized grains – better
Silt soils
drainage than clay soils
• __________
- large-grained, do not retain
Sandy soils
water
• Most soils are a mixture
loam
equal parts
• ______
- silt and sand in roughly _____
Factors That Affect Soil
• ________
- most important factor that
climate
determines the type of soil that is formed
• Climate affects _________
- increased rainfall,
weathering
warm temperatures, frost-thaw etc.
• __________
- minerals in the rocks affect the
Kinds of rock
characteristics of the soil – example: reddish
colored soil indicates iron-rich minerals
• __________
- mix the soil and breakdown
earthworms
organic matter
Soils Continued
• Soil color is affected by the amount of
__________
Organic matter in the soil.
darker
• Soils with more organic matter are ______
Shape of land
• ___________
- affects soil formation because
of slope and erosion
topsoil
• Mountains have thin layers of ______
• Land that is flat has a Thick
_________
of topsoil
layer
because of minimal erosion
Assessment
• Write an advertisement for an ideal soil for
growing plants.