Mineral and Rocks
Unit
Lessons Included
Minerals
Igneous
Rocks
Sedimentary Rocks
Metamorphic Rocks
Minerals
Table of Contents
1.
Minerals Defined
a. Mineraloids
b. Industrial Minerals
c. Biochemical Minerals
2.
3.
4.
5.
Characteristics of Minerals
Crust Composition
Examples of Various Mineral
Compositions
Crystalline Form
1. Minerals Defined
a.
A mineral is the
basic material that
makes up the earth’s
crust and has the
following
characteristics:
1.
2.
3.
4.
Naturally occurring
Inorganic
Has a fixed chemical
composition
Has an orderly
internal arrangement
of atoms.
1. Minerals
b.
c.
d.
Mineraloids-Lack
crystal structure
(Examples include rare
gemstones)
Industrial MineralsUsed for manufacture of
physical materials.
Biochemical MineralsCan be manufactured by
organisms (Example:
Aragonite-Made by clams
to produce their shells)
2. Characteristics of Minerals
a.
b.
c.
Naturally Occurring- Formed as a
result of natural processes in or on the
earth
Inorganic- Came from things that were
never alive.
Fixed Chemical Composition- Use of a
chemical formula or symbol to represent
what mineral is made of.
1. Some minerals found as pure elements (Cu,
Ag), most are found as compounds
(Calcite(CaCO3), Quartz(SiO2).
3. Composition of Crust
**98% of the crust is made of just 8 elements, even though
there are over 100 known elements ( Pg 11 of ESRT)
Element
% by Mass
Oxygen
46.40
Silicon
28.15
Aluminum
8.23
Iron
5.63
Calcium
4.15
Sodium
2.36
Magnesium
2.33
Potassium
2.09
Nitrogen
Hydrogen
Other
0.66
Composition of Crust
4. Examples of Various Mineral
Compositions
Mineral
Chemical Name
Chemical Formula
Calcite
Calcium Carbonate
CaCO3
Galena
Lead Sulfide
PbS
Gypsum
Calcium SulfateWater
CaSO2 +2H2O
Olivine
Magnesium Silicate
Mg2SiO4
K-Feldspar
Potassium aluminum
silicate
KAlSi3O8
Pyrite
Iron Sulfide
FeS2
Quartz
Silicon dioxide
SiO2
Pictures of Minerals
5. Crystalline Form
a.
b.
c.
Atoms or molecules of a mineral are the same
throughout that mineral
There is a definite repeating pattern in minerals,
if pattern is large enough to be seen it is called a
crystal.
Internal structure determines outside structure.
5. Crystalline Form Cont.
d. The shape of the
mineral’s crystals is a
result of its atomic
arrangement
5. Crystalline Form
a.
b.
c.
Atoms or molecules of a mineral are the same
throughout that mineral
There is a definite repeating pattern in minerals,
if pattern is large enough to be seen it is called a
crystal.
Internal structure determines outside structure.
5. Crystalline Form Cont.
d. The shape of the
mineral’s crystals is a
result of its atomic
arrangement
Use your Earth
Science Reference
Tables (ESRT) page
16 when identifying
an unknown mineral!
6. Identifying Minerals


There have been
over 2000 minerals
identified.
They can be
classified by both
physical and
chemical
properties.
7. How to Identify Minerals
Color- First property
usually observed.
a.
•
•
•
•
Very unreliable way to
identify minerals
Many minerals come
in a variety of colors
(Quartz)
Some minerals have
same color (Pyrite
(FeS2) and Gold (Au))
Due to impurities
The many colors of Fluorite
7. Identifying Minerals
b.
Luster- The way
a mineral reflects
light from it’s
surface.
•
•
NonmetallicGlassy, brilliant,
greasy, oily, waxy,
silky or earthly.
Metallic- Has
metallic properties
7. Identifying Minerals
d.
Hardness- The
ability for a mineral
to resist being
scratched.
• The hardness of a
mineral is usually
stated in terms of
Moh’s scale of
hardness
• A harder material
can always
scratch a softer
material but a
softer one cant
scratch a harder
7. Identifying Minerals
e.
Cleavage- The
tendency of a
mineral to break
parallel to atomic
planes in it’s
crystalline
structure.
•
Ex. Mica- Breaks
in parallel layers
7. Identifying Minerals
f.
Fracture- When
minerals break
unevenly because all
planes are equally
strong in all
directions.
a.
b.
c.
d.
Conchoidal- Smooth,
curved break that looks
like a shell
Fibrous or splinteryFibers
Hackley- Jagged sharp
edges (Native Metals)
Uneven
Mica
Halite
Galena,
Pyrite
Calcite
Fluorite
Feldspar
8. Alternate ways to Identify
Minerals
a.
b.
Specific GravityThis is a ratio off
the density of a
mineral compared
to the density of
water. (NO UNITS)
Chemical TestsUse of HCl tests for
calcium carbonate,
if mineral contains
it will bubble or
effervesce. (Calcite,
Dolomite)
8. Alternate ways to identify
Minerals
c. Magnetism- Minerals that contain iron,
copper or nickel will attract a magnet.
9. Major Mineral Groups
a.
b.
Silicates- One ion of
silicon is attached to
4 ions of oxygen in
the shape of a
tetrahedron. Bonds
are strong.
Sulfides- When 1 or
more sulfur ions
combine with a
metallic ion (PbS,
FeS, ZnS)
9. Major Mineral Groups
c.
d.
•
•
•
Oxides-Compounds in
which Oxygen is
joined with ions of
other elements,
usually metals.
(Fe2O3,FeO).
Carbonates and
Sulfates- Minerals
contain Oxygen, the
oxygen ion join with
other ions to form
polyatomic ion
Carbonate ion (CO3)^-2
Sulfate ion (SO4)-2
HANDOUT
8. Alternate ways to Identify
Minerals
a.
b.
Specific GravityThis is a ratio off
the density of a
mineral compared
to the density of
water. (NO UNITS)
Chemical TestsUse of HCl tests for
calcium carbonate,
if mineral contains
it will bubble or
effervesce. (Calcite,
Dolomite)
8. Alternate ways to identify
Minerals
c. Magnetism- Minerals that contain iron,
copper or nickel will attract a magnet.
9. Major Mineral Groups
a.
b.
Silicates- One ion of
silicon is attached to
4 ions of oxygen in
the shape of a
tetrahedron. Bonds
are strong.
Sulfides- When 1 or
more sulfur ions
combine with a
metallic ion (PbS,
FeS, ZnS)
9. Major Mineral Groups
c.
d.
•
•
•
Oxides-Compounds in
which Oxygen is
joined with ions of
other elements,
usually metals.
(Fe2O3,FeO).
Carbonates and
Sulfates- Minerals
contain Oxygen, the
oxygen ion join with
other ions to form
polyatomic ion
Carbonate ion (CO3)^-2
Sulfate ion (SO4)-2
HANDOUT
Remember…
Your ESRT pg 16 lists all the
mineral information you will
need to identify an unknown
mineral sample!
Igneous Rocks
Table of Contents
1.
2.
3.
4.
5.
Formation of Igneous Rocks
Characteristics of Igneous Rocks
a.
Texture
b.
Mineral Composition
Textures of Igneous Rocks
a.
Intrusive
1.
Pegmatic (Very coarse grained)
2.
Phaneritic (Coarse grained)
b.
Extrusive
1.
Aphanitic (Fine Grained)
2.
Glassy
3.
Vesicular (Gas Bubbles)
4.
Pyroclastic (particles from volcano)
c.
Intrusive and Extrusive
1.
Porphyritic
Mineral Composition
a.
Felsic
b.
Mafic
How to Identify Igneous Rocks
Igneous Rock ID Chart
Page 6 of ESRT
1. Formation of Igneous Rocks
a.
b.
c.
d.
Form as the result of
cooling or solidification of
Magma.
LIQUID HOT MAGMA

Mixture of hot liquid rock,
gases and crystals

Less dense than
surrounding rock so it
moves upward
Magma that reaches surface
(lava) erupts and solidifiesExtrusive IR
Magma that cools
underground-Intrusive IR
2. Characteristics of Igneous
Rocks
a.
Texture- The size, shape and
arrangement of the mineral
crystals or grains of rocks.
•
Slow cooling- Large
Crystals, intrusively
formed
•
Rapid cooling- Small
Crystals, extrusively
formed
b. Mineral Composition- Minerals
that make up the rock. Made
of a combination of 8.
(Muscovite and biotite mica,
Quartz, Potassium and
Plagioclase Feldspar,
Amphibole, Pyroxene and
Olivine)
Pictures of 8 minerals that
comprise Igneous Rocks
Felsic
Mafic
3. Textures of Igneous Rocks
a. Intrusive (Plutonic)
Magma trapped
underground and
solidifies. As a
result of slow
cooling large
crystals are able to
form.
3a. Intrusive Igneous Rocks
1.
2.
Pegmatic (Very
Coarse)- Crystals
>10mm, very slow
cooling. (Pegmatite)
Phaneritic (Coarse)
Crystals 1-10mm,
slow cooling. Granite
and (Gabbro)
3. Textures of Igneous Rocks
b. Extrusive
(Volcanic) Formed
from the rapid
cooling of lava
result the rock has a
very fine structure
and sometimes
none at all
3b. Extrusive Igneous Rocks
1.
2.
3.
4.
Aphanitic (fine texture)
crystals <1mm.(Rhyolite)
Glassy- Result of rapid
cooling no visible crystals
at all. (Obsidian)
Vesicular- Rapid cooling of
gas filled lava, has holes.
(Pumice)
Pyroclastic- Particles
emitted from volcanoes.
3c. Intrusive and Extrusive
1. Porphyritic- Has both
small and large
crystals. Result of
cooling undergroundLarge Crystals
(Phenocrysts) and
rapid cooling above
ground (Groundmass or
matrix)
4. Mineral Composition
a.
b.
Felsic Group- Igneous rock
contains mostly Quartz,
Potassium and Plagioclase
Feldspar, tend to be light
colored and low density.
Mafic Group- Igneous rock
contains mostly Olivine,
pyroxene, and amphibole,
tend to be dark colored
and higher in density.
5. How to Identify Igneous Rocks
Identify rocks color index
1.
•
•
Light Colored- Felsic
Dark Colored- Mafic
Identify mineral composition by Color
index.
3. Identify Rocks Texture
2.
•
•
Intrusive- large crystals
Extrusive- Small or no crystals or gas bubbles.
Sedimentary
Rocks
Table of Contents
1. Sediments
2. Sedimentary Rocks Defined
3. Formation of Sedimentary Rocks
4. 3 Types of Sedimentary Rocks
a. Clastic
•
•
•
Grain Size
Grain Shape
Grain Arrangement
b. Chemical
c. Organic
5. How to Classify Sedimentary Rocks
1. Sediments
a. These are loose
grains and chemical
residues of Earth
materials
1. Formed by:
•
Chemical and
Physical weathering
2. Sedimentary Rocks Defined
a.These are rocks that form when sediments are
compressed together or otherwise hardened , or
when masses of inter-grown mineral crystals
precipitate from water.
3. Formation of Sedimentary Rocks
a.
Lithification- The
hardening of sediment
to produce rock.
Usually occurs in
layers.
1.
2.
3.
Compaction- Increased
pressure from overlying
sediment
Cementation- Binding
together of sediments
Precipitation- When sea
water evaporates leave
aggregates of intergrown
and interlocking crystals
Sedimentary Rock Identification
Chart (Page 7 ESRT)
4. 3 types of sedimentary rocks
a.CLASTIC – formed from fragments of other
rocks
– Sandstone, Conglomerate
b.CHEMICAL – formed from the mineral
precipitates of evaporated seawater
– Rock Salt
c.ORGANIC – formed from the remains of
plants & animals with rock fragments
– Coal, Fossil Limestone
4a.
CLASTIC
• Formed when rock
fragments & sediment
are carried & deposited
by WIND, GLACIERS, &
RUNNING WATER
• Sediments are
DEPOSITED, then
COMPACTED & finally
CEMENTED together
4a1. Grain Sizes of Clastic
Sedimentary Rocks
Based on Wentworth scale
Gravel- Grains >2mm (Boulders, pebbles)
Sand- Grains 1/16mm to 2mm (Sandbox)
Silt- 1/256mm to 1/16mm (too small to see)
Clay- <1/256mm (too small to see)
Pictures of Rocks With Specific
Grain Size
Grain Size
Sediment
Rock name
Larger than 2mm
Gravel
Conglomerate
2mm to 0.06mm
Sand
Sandstone
0.06 to 0.002mm
Silt
Siltstone
Smaller than 0.002mm
Clay
Shale
4a2. Grain Shape of Clastic
Sedimentary Rocks
Grain Shape- Sediments can be transported over
a great distance by wind water and ice.
1. Angular- Transported short distance
2. Rounded- Traveled longer distance
3. Well Rounded- Traveled very long distance.
Well Rounded----------------------------------------------------------Angular
4a3. Grain Arrangement of Clastic
Sedimentary Rocks
Grain Arrangements- Different velocities of wind and
water currents capable of transporting and separating
different densities and sizes of sediments
1.
2.
Poorly Sorted- Many different sizes
Well Sorted- All grains same size
Poorly Sorted------------------------------------------------Well Sorted
Stream Velocity versus Particle
Size
4b.
CHEMICAL
• Formed when dissolved minerals in seawater
are deposited (seawater evaporates, leaving the
minerals behind)
• Usually old swamps, seas, or lakes evaporate
• Also known as CRYSTALLINE because of the
fine crystals
– Limestone, Rock Salt, Rock Gypsum (sheetrock)
Salt “Mines” - Rock Salt is being formed
as the salt water evaporates from the sea.
“Devil’s Golf
Course” –
millions of
years ago this
was a sea of
salt water. It
has been
evaporating
over time…
…and has formed
“pockets” of
chemical
limestone, rock
salt, and rock
gypsum!
4c. ORGANIC
• Formed from the remains of plants &
animals that are compacted
– Fossil Limestone – formed when shell
remains of marine organisms are
cemented in fragments
• Shells are made of CALCITE which reacts with
acid and is a natural “cement”
Brachiopod fossils in limestone
Trilobite fossils – over 250 MILLION years old!!!
Imprint
of a leaf
If peat at the bottom of a
swamp is buried &
compressed, coal may form
Coal –
note
distinct
layering
of peat
5. How to Classify Sedimentary
Rocks
1. Determine rocks general composition
(Clastic, Organic or Chemical)
2. Describe rocks texture
•
•
•
Grain Size
Grain Shape
Grain Arrangement
3. Determine rocks name by using flow
chart
Metamorphic
Rocks
Table of Contents
1.
2.
Metamorphic Rocks Defined
Ways Metamorphic Rocks form.
a.
b.
c.
3.
Types of Metamorphism
a.
b.
4.
Regional
Contact
Textures of Metamorphic Rocks
a.
b.
5.
Heat
Pressure
Chemical Activity
Foliated
Non-Foliated
How to identify a Metamorphic rock using the handout.
1. Metamorphic Rocks Defined
Metamorphic- From
Greek meaning “of
changed form”.
b. Metamorphic Rocks
are rocks changed
from one form to
another by heat,
a.
pressure or the
action of hot fluids.
1. Metamorphic Rocks Defined
c.Every metamorphic
rock has a parent rock
in which it can come
from it can be:
 Igneous, Sedimentary
or even metamorphic.
d. Examples
 Conglomerate
Metaconglomerate
 Sandstone Quartzite
 Limestone Marble
2. Ways Metamorphic Rocks Form
a.
b.
Heata. Expansion atoms move
apart bonds stretched
and weakened
•
Extreme heat Result of
deep burial Magma
formation New minerals
made
Pressurea.
Compaction atoms
move closer stress
causes bonds to break
3. Types of Metamorphism
a.
Contact- Occurs locally, over
short periods of time and
adjacent to Igneous
Intrusions.
•
Intensity is greatest at
contact between parent
rock and intrusive magma.
Intensity decreases with
increasing distance.
•
(High Grade)-Gneiss,
Schist, phyllite, Slate-(Low
Grade) SHALE (SR)
3. Types of Metamorphism
Regional-Occurs
over large areas,
accompanied by
folding rock layers
and mountain
building.
b.
•
Causes- Large
igneous intrusions
that form and cool
over long periods.
4. Textures of Metamorphic Rocks
►
a.
b.
Two main groups:
Foliated or Non foliated
Foliated- Mineral
Alignment Mineral are in
layers usually Mica
Banding- Alternating
layers of different
colored minerals
(Distorted by heat and
pressure)
More
foliation
– slate &
phyllite
Foliation – note the
“scratches” in the rock –
this is mineral alignment!
Banding – mica
schist
Excellent
example
of
banding &
distortion
– this is
GNEISS

Metamorphic mountains formed
from regional metamorphism
Alaska’s Copper Mountain – contact metamorphism
4a. Foliated Metamorphic Rock
Texture
Slaty rock
Cleavage- Very flat,
parallel, closely
spaced shear planes.
(Slate)
2. Phyllite TextureWavy or wrinkled
foliation- Rock has
metallic luster.
(Phyllite)
1.
4a. Foliated Metamorphic Rock
Texture
3. Schistosity- Scaly or
glittery layering of platy
minerals (Schist)
4. Gneissic BandingAlternating layers or
lenses of light and dark
medium to coarse
grained minerals.
(Quartz, Feldspar-Light
bands, Ferromagnesium
–Dark bands
4. Textures of Metamorphic Rocks
b.
Nonfoliated- No obvious
layering
1.
2.
3.
4.
Crystalline- Medium to
coarse grained of
intergrown, equal sized
visible crystals (Marble)
Microcrystalline- Fine
grained intergrown
crystals. (Hornfels)
Sandy- Medium to coarse
grained fused sand sized
grains. (Quartzite)
Glassy- No visible grains.
(Anthracite coal)
5. How to Identify Metamorphic
Rocks
1.
2.
3.
4.
Determine if rock is foliated or non-foliated
and what other textual features are
present.
List minerals in order of increasing
abundance.
Determine Metamorphic rock name
Find out what parent rock is