3-7-11
Aim: What is a Mineral?
Do Now:
Define Mineral.
HW: R&H pp. 218-222, A&E #1-15
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Mineral- a mineral is a naturally occurring,
inorganic, solid, with a definite chemical
composition and crystal structure.
Naturally occurring- happens on its own in
nature without human assistance.
Inorganic- not living and is not made of living
things.
Solid- definite shape and definite volume
Definite chemical composition- the same mix
of elements all the time.
Definite crystal structure- atoms arranged in a
repeating pattern that forms a crystal shape.
Mineral Properties and Identification.
A mineral’s physical properties are based on its
internal arrangement of atoms
• Color- what color the mineral appears- not the
best test because many minerals have the same
color and impurities may affect the color.
• Streak- shows the mineral in its powdered form
against a white tile. A better sense of the
minerals color.
• Luster- the way a mineral reflects light. There are
many lusters but we will look it metallic (looks
and shines like metal) or nonmetallic ( does not).
• Hardness- a minerals’ resistance to scratching.
Mineral Identification cont’d.
• Density- how compact the molecules are D= M/V.
• Cleavage- the tendency of a mineral to break along flat
planes. A mineral can have 0,1,2,or 3 planes of
cleavage. A plane is a direction of break and if there
are 3 than the shape is cubic.
• Crystal Structure- the way the atoms are arranged
creates a definite repeating crystal shape.
• Special properties- some minerals have a distinct smell,
are magnetic, can glow in the dark or something else
unique to the mineral that helps to identify it. Also
some minerals will react with certain chemicals i.e.
hydrochloric acid will fizz in the presence of calcite.
3-10-11
Aim: What is a Sedimentary Rock?
• Do Now: Read p.219 “Mineral Crystal
Structure” and diagram on p.220.
• 1. What is a tetrahedron?
• 2. What is a tetrahedron made up of?
• 3. What is the tetrahedron responsible for?
• HW- R&H pp. 223-226
Rocks-solid substances containing 1 or more
minerals. All rocks contain minerals.
• Monominerallic- rocks containing one mineral
type only (can be both a mineral and a rock.
• Polyminerallic- most rocks contain a mixture
of minerals, not in definite amounts.
• Rock Types- there are three types of rocks that
differ in their environment of formation (R.T.
p.6). Sedimentary, Igneous, Metamorphic.
Sedimentary Rocks- form from the depostion,
buriel, compaction and cementation of
sediments.
• Sedimentary rocks are formed at or near the
earth’s surface, usually under large bodies of
water.
• Sediments are deposited, buried by other
sediments forcing them to compact. Then
minerals dissolved in the water work as a glue to
cement the sediments together creating a
sedimentary rock. See R.T. p.7 for these rocks.
• The sediments can be broken pieces of other
rocks, shells, plant and animal remains, or
chemical precipitates or evaporites ( the solid left
after water evaporates).
How to identify a sedimentary rock?
• Texture – grain size- measure the size of the
grains in the rock (clay, silt, sand, pebbles,
etc.)
• Layers of sediment.
• Cemented together……….. Could be
sediments, shells, fossils or crystals from
chemical precipitates or evaporites
Sedimentary Rocks
3-14-11
Aim: What is an Igneous Rock?
• Do Now:
• 1. What is an evaporite and give an example of a
rock that results?
• 2. What is a precipitate and give an example of a
rock that results?
• 3. What are the two organic sedimentary rocks
on the R.T.?
• HW- Finish Igneous Rock Lab
Igneous rocks form from the
Solidification of Magma
• What determines the size of the crystals in an igneous
rock is how fast the magma cools.
• The longer it takes to cool the bigger the crystals have
an opportunity to grow.
• Rock cools slowly deep below the surface creating
large intergrown crystals.
• Rock cools quickly at the surface forming small to no
crystals.
• Quiet lava flows produce glassy igneous rock (noncrystalline), while explosive eruptions produce
vesicular rock (containing gas pockets)
• If the cooling rate of magma gets interrupted by
another lava flow you can get a rock that has fine
crystals with larger ones mixed in (porphyritic).
Igneous Rocks
3-15-11
Aim: What is a Metamorphic Rock?
• Do Now:
1. Where and how does a rock with large
intergrown crystals form?
2. As cooling time increases crystal size_______.
HW: R&H pp.226-232, A&E # 16-37, Topic 11 exam
Thursday.
Metamorphic Rocks form as a result of heat and
pressure or chemical change to pre-existing
rocks.
• Can form deep underground where the heat and
pressure is great causing recrystallization without
true melting.
• Rocks are distorted in structure- could be crystal
distortion, fossil distortion, layer distortion
• Rocks are baked under the heat and pressure and
become foliated (the appearance of peelable
layers), could be fine, medium or course
foliation.
Types of Metamorphism (2)
1. Regional Metamorphism- when a large area is pushed
further down in the crust resulting in tremendous
heat and pressure.
2. Contact Metamorphism- when rock comes in contact
with an igneous intrusion the rock touching the
intrusion gets heated and pressurized creating zones
of metamorphic rock.
Metamorphic Rocks
3-16-11
What is a Mineral Resource?
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Do Now: R&H pp.234-237
1. Answer aim question.
2. What is a renewable vs. a nonrenewable resource?
3. What is a fossil fuel and are they renewable or
nonrenewable?
• 4. Why does metamorphic rock tend to be more dense
than the other types of rock?
• 5. What is foliation?
• HW: A&E p.237 #38-47, study T.11 for exam Friday.