Transcript UNIT 3 MINERALS, ROCKS, AND RESOURCES

MINERALS AND
ROCKS UNIT
I. Atoms – Building blocks for matter
Each atom on the periodic table is…
Unique
 Identified by the mass and number of electrons
 Combine with other atoms in a predictable
manner
A Unit 2 Need to know:
Atoms MAKE elements MAKE minerals MAKE rocks
II. Minerals –
Naturally occurring, inorganic (nonliving), homogeneous (uniform), solid
materials with a definite chemical
composition, molecular structure, and
specific physical properties.
Quartz (SiO2)
There are between 2,0003,000 known
Minerals on Earth.
Which of the following are minerals?
1. Copper
in pipes and wire
2. Table
salt
5.3.
4.used
Oil
Sugar
A Tree
No,
Not
a mineral
b/c
it’s
living
No,
Not
a
mineral
b/c
it’s
living
No,
Not
a
mineral
b/c
it’s
a
liquid
Yes,
it’s
a
mineral
Yes, it’s a mineral
A. Mineral Formation –
1. Cooling of Magma/Lava – Liquid "rock" cools
allowing various atoms to become arranged into
crystalline solids.
A Crystalline solid is a solid in which the atoms
are arranged in a regular and repeating pattern.
2. By Evaporation – Solid deposits left after water
has evaporated. Called Evaporites
Important! Two minerals with the same chemical composition may
have very different properties because of
HOW THE ATOMS ARE ARRANGED
e.g. graphite and diamonds are both made of carbon but differ
greatly in their hardness.
B. Crustal Composition
ESRT Page 1: Composition of Earth’s Crust
Oxygen is the most abundant,
Silicon is the second most
Although there are thousands of known minerals
on Earth, most of the Earth’s crust is made of
only 8 common elements (~98%).
C. Mineral Composition
ESRT Page 16: Properties of Common Minerals
Look here…
D. Mineral Groups – Based on the
common elements or compounds.
Some facts…
 the Silicates – SiO2
Largest group (made of the 2 most common elements)
Based on a crystal structure called the
SILICATE TETRAHEDRON
Different arrangements of the Silicate Tetrahedron
lead to different silicate minerals.
Others…
2. the Oxides – O in common
3. the Sulfides – S in common
4. the Carbonates – CO3 in common
Important: A carbonate Bubbles/Fizzes with
exposed to acids including Acid Rain.
Fortunately, Minerals have specific
physical and chemical properties which
make them identifiable.
F. Physical Properties of Minerals –
How do these
mineral look
different?
1. Color – Characteristic color of a mineral.
Many minerals have more than one color.
Which one is gold??
GOLD
NOT A GOOD IDENTIFIER because many
minerals have more than one color.
Which one is Quartz?
All of them
2. Hardness – A measure of how easily a mineral
can be scratched.
Moh’s hardness scale
3. Streak – Color of the powder of a mineral
when crushed or scratched across a streak
plate (unglazed porcelain).
4. Luster – How light is reflected from a minerals
surface. Either metallic or non-metallic
Metallic or Nonmetalic?
metallic
nonmetallic
nonmetallic
A mineral breaks by either…
5. Cleavage – Minerals
that break into smooth,
flat pieces.
6. Fracture – Minerals that
break into jagged pieces.
Minerals either have cleavage or fracture
7. Crystal Form – Characteristic shape of the
mineral. Based on the arrangement of
atoms.
8. Chemical and Special Properties of Minerals
Many minerals possess other unique properties that
add in the identification such as: taste, reaction to
acids, magnetism fluorescence phosphorescence,
double refraction, radioactivity, etc.
Under a black light
The main idea here is:
All properties of minerals are based on:
1. The composition of atoms/elements
2. How the atoms are arranged
Know this!!!
Salt mines…
F. Mineral Resources and Natural Resources –
Natural, inorganic or fossilized organic materials in or on the
earth’s crust that are of human use and economic value
Examples: water, forests, soil, gold, coal, oil, etc.
Where do minerals come from?
Below ground mining
Open pit mining
Steel Making
Virtual Cement
Plant Tour |
Portland Cement
Association (PCA)
Conservation of Minerals
and Natural Resources
As the human population
on Earth continues to
increase at it rapid rate,
the availability of mineral
and natural resources will
decrease
What can be done about that?
Remember the 4 R’s – REDUCE,
REUSE, RECYCLE, RECLAIM
YouTube - Computer Recycling

Renewable vs. Nonrenewable resources
Resources that are being consumed in amounts greater
than they can be replenished are nonrenewable.
III. Rocks - Made of minerals.
How are rocks and minerals different?
They can be either:
1. Mono-Mineralic – Composed of only
one mineral.
2. Poly-Mineralic – Composed of two
or more minerals. (i.e. granite)
calcite
Three types exist:
Igneous
Sedimentary
Metamorphic
Rocks are distinguished from one another based on their origin.
ESRT Page 6 - Rock cycle in Earth’s crust
B. Igneous rocks (ignis=greek for fire)
1. Formation – From the cooling, solidification,
crystallization of magma or lava.
What is the difference between lava and magma?
Igneous rocks make up 95% of Earth’s rocks
Insert Picture Here
Why no picture of magma?
2. Classification –Based on CRYSTAL SIZE
and COLOR.
a. Crystal Size is determined by
the cooling environment.
Outside the Earth
Inside the Earth
i. Intrusive – Form BELOW the Earth’s surface –
Plutonic Igneous Rocks
Texture – Large mineral grains that are
visible to the naked eye.
Nice to Know: Phaneritic Texture
Formation – From MAGMA that cools
slowly
Examples: granite and gabbro
ii. Extrusive – Form ABOVE the Earth’s
surface – Called Volcanic Igneous Rocks
Texture – Small mineral grains that ARE
NOT visible.
Nice to know: Aphanatic Texture.
Formation – Form from LAVA that cools
rapidly
Examples rhyolite and basalt
Which diagram below shows the
igneous rock that cooled the fastest?
Which diagram
shows the igneous
rock that cooled the
slowest?
b. Color – Determined by the Mineral Composition
i. Felsic – Light-colored igneous rocks
usually rich in feldspar (fel-) and silica (sic).
Quartz is usually present.
ii. Mafic – Dark-colored igneous rocks usually
rich in magnesium (ma-) and iron (-Fe).
Amphibole and pyroxene usually present.
Bowen’s reaction series provides a Model for Igneous rock
formation and explains how rocks can contain different minerals.
1100°
C
1100°C
560°C
1. Name the 2 minerals that crystallize first (highest temperatures)
2. What is the last mineral to crystallize?
3. Why is quartz composed only of Silicon and Oxygen?
4. What elements remain in the “soup” after biotite forms? (hint: last page of ESRT’s)
2. Reading the ESRT’S - Page 6 - Scheme for
Igneous Rock Identification
Look at GRANITE:
First, moving horizontally
to the right, over to the
column labeled as
“texture”, you can see that
it is coarse grained.
Next, moving vertically
down, you can see that it is
light in color, low in
density, and considered
felsic.
What
minerals
can(plutonic)
be foundorinextrusive
granite?(volcanic)?
Is granite
intrusive
Do now – page 14 in your notes
Try these:
1. What extrusive igneous rock has a fine texture
and is dark in color?
2. What coarse-grained igneous rock has a mineral
composition over 75% pyroxene?
3. What volcanic igneous has contains about 50%
potassium feldspar and about 35% quartz?
4. What volcanic igneous rock has a glassy texture
and has quartz present in its mineral composition?
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Going further…
It is known that granite is usually found on continents and
basalt is found on the ocean floor. Why do you think this
so? (Hint: think of the main earlier this year – that D
word)
Where we are going today
B. Sedimentary Rocks – Rocks made from the remains
of other rocks, organic life forms (biological) or chemically
dissolved materials that, over time, get changed into rock.
Make up approximately 75% of the rocks on the
SURFACE of the Earth.
1. Formation – Sedimentary rocks may be formed by either
Compression/Cementing or evaporation.
a. Compression and
Cementing – Inorganic
sediments or organic remains
that have been transported
(eroded), deposited into piles
(buried), then change into rock.
Erosion generally leads to rounded sediments
Deposition generally occurs in large bodies of water
I. Compression/Compaction – As sediments or organic
remains pile up, the underlying layers become compressed
II. Cementation – Natural glues hold sediments or organic
remains together
Natural cements may include silica, iron, lime,
and/or clay.
Virtual Cement Plant Tour | Portland Cement Association (PCA)
b. Evaporation – Sedimentary rocks that form from minerals
that are dissolved in water where the water evaporates away
leaving behind the minerals.
This process is also
called precipitation
These are called EVAPORITES and are referred to as the Crystalline
Sedimentary Rocks. These are usually monominerallic.
2. Classification:
a. Sedimentary rocks that form by Compression
and Cementing are classified as either:
Clastic Sedimentary Rocks (from the Greek
word for broken – klastos) –
Rocks that form from inorganic sediments
Conglomerate
Classification based on the size of the
sediment it formed from ex. Sand, Gravel,
Pebbles, etc.
 Bioclastic Sedimentary Rocks – Rocks that form
from sea shells and other organic remains.
Coquina
Coal
Classification based on the type of
organic remains they form from
b. Classification of Crystalline Sedimentary
Rocks is based on the composition of the minerals
they formed from.
All Sedimentary Rocks usually have one or both of
these features:
3. Stratification – Sedimentary
rocks are usually layered horizontally
with the bottom layered being the oldest.
4. Fossils – Because of the absence of
EXTREME heat and pressure, fossils
will usually only be found in
Sedimentary Rocks. IMPORTANT!!!
The presence of fossils also provides evidence for the environment
in which the rocks formed. Seashells would indicate a marine
environment whereas footprints would indicate a land environment.
. C. Metamorphic rocks – CHANGED ROCKS
(meta=change, morph=form)
1. Formation – Form when sedimentary, igneous, or even
metamorphic rocks are exposed to conditions of extreme HEAT
and PRESSURE.
These conditions are found deep within Earth
The original rock from which a metamorphic rock forms
is called the PARENT ROCK.
Metamorphic Rocks
sometimes indicate the
collision zone between
two tectonic plates.
Ex. The Himalayas
Features of a Metamorphic Rock May include:
Distorted layers
Continued or new mineral growth
Alignment of minerals
Separation of minerals
Metamorphic rocks are commonly identified by
BANDING AND DISTORTION
2. Classification
a. Foliated – An alignment of minerals or the
separation of minerals into platy (flaky) layers or light
and dark bands.
Examples:
1). Slate – Was shale
2). Gneiss –Was granite
3). Schist – Was granite
Because slate shows the least amount of
change, it has undergone only moderate
metamorphism (low-grade).
b. Non-Foliated – No noticeable alignment or banding
of minerals.
Examples
1) Marble – Was limestone
Non-foliated rocks can be identified by their crystalline
appearance
3. Types of Metamorphism
a. Regional Metamorphism – Occur deep within the
Earth and across large areas. Usually associated with
an orogeny (mountain building).
b. Contact Metamorphism – BAKED ROCKS Form
where a parent rock is near or in contact with an
igneous intrusion – usually confined to small areas.
A variation to this occurs
when the metamorphism
is done by extremely hot
water – THERMAL
METAMORPHISM
YouTube - Old Faithful Geyser

The AVERAGE interval between Old Faithful's
eruptions is 90 minutes. The range between eruptions is
from 35 minutes to 2 hours. An eruption can last from 1.5
- 5 minutes and can spray as high as 90 to 184 feet.
What metamorphic
would form at E?
A do now…
Try these from page 21 in your notes:
1. What type of metamorphism do all foliated
metamorphic rocks undergo?
2. What is the parent rock for a quartzite?
3. What type of metamorphic rocks are being formed
where the Himalayas are?
What is the origin of the rocks pictured to the right?
4 teams enter a marathon (42 km) – The green team, red team, blue
team, and white team. The team statistics are below:
Green team: 5 runners who trained for a 5 km race
Red team: 10 runners who trained for 5 km and 10 km races
Blue team: 15 runners who trained for 5 km, 10, km, and 21 km
White team: 20 runners who trained for 5 km, 10 km, 21 km, and
42 km races.
A 5 km, who is dropping out of the marathon?
At 18 km, who is running the race? why