Class Notes: Minerals and Rocks - Earth...

I. Minerals

• Minerals are the ingredients needed to form the different types of rocks

• Rock - ! ______________________________________________________________________________

! _____________________________________________________________________________________

• Mineral - ! _____________________________________________________________________________

! _____________________________________________________________________________________

• Inorganic - ! ___________________________________________________________________________

! _____________________________________________________________________________________

• Crystalline - ! __________________________________________________________________________

! _____________________________________________________________________________________

• Minerals form by three methods:

1. Crystallization - a process of organizing ________________ to form crystalline solids

2. Recrystallization - the cooling and hardening of _________________ or magma into minerals

3. Rearrangement - the realignment of atoms in minerals under high !______________________and _________________________

• Most rock forming minerals are silicates that result in a tetrahedron shape

• Four-sided units of 4 ____________________ and 1 ____________________

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Class Notes: Minerals and Rocks

Name: ___________________________________________ Minerals and RocksDate: __________________________ Period: ___________ The Physical Setting: Earth Science

• Crystal structure or “_____________________________________________________” are responsible for the physical and chemical properties a mineral possesses

• Each mineral has a set of physical and chemical properties that can be used to identify the sample

• The methods we use to classify minerals are:

1. Color - a visual attribute of an object based on perception

• One of the most obvious, but not the most reliable

• Many of the 4000 known minerals share similar colors

2. Streak - ! _______________________________________________________________________

! ______________________________________________________________________________

• Weathering changes the outside color, but streak gives the true color

3. Luster - ! _______________________________________________________________________

! ______________________________________________________________________________

• Two types of luster:

• Metallic Luster - shines like stainless steel

• Nonmetallic Luster - earthy or dull shine

4. Density - ! ______________________________________________________________________

! ______________________________________________________________________________

• Sample Problem: a student measures the mass of a mineral to be __________ g and calculates the volume to be __________ mL. What is the density?

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Write the Formula:

Show All Work:

Answer:


• The methods we will use are (continued):

5. Hardness - ! ____________________________________________________________________

! ______________________________________________________________________________

• Mohs Hardness Scale is used to classify hardness

6. Cleavage - !____________________________________________________________________________________________________________________________________

• Mohs Hardness Scale is used to classify hardness

7. Fracture - ______________________________________________________

! ______________________________________________________________________________

• Tends to lack preferred zones of weakness

8. Acid Test - ! ____________________________________________________________________

! ______________________________________________________________________________

• Calcite and Dolomite both react with acid

Hardness Mineral Test

1 Talc Finger nail scratches easily

2 Gypsum Finger nail scratches

3 Calcite Copper penny scratches

4 Fluorite Steel knife scratches easily

5 Apatite Steel knife scratches

6 Feldspar Steel knife will not scratches

7 Quartz Will scratch glass and steel

8 Topaz Harder then any common mineral

9 Corundum Scratches topaz

10 Diamond Hardest mineral

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II. Igneous Rocks

• Igneous Rocks - ! ______________________________________________________________________

! _____________________________________________________________________________________

• Methods to classify igneous rocks:

1. Environment of Formation - ! ______________________________________________________

! ______________________________________________________________________________

• Magma - ! _______________________________________________________________

! _______________________________________________________________________

• Plutonic - ! _______________________________________________________________

! _______________________________________________________________________

• Intrusive - ! _______________________________________________________________

! _______________________________________________________________________

• Lava - ! __________________________________________________________________

! _______________________________________________________________________

• Volcanic - ! _______________________________________________________________

! _______________________________________________________________________

• Extrusive - ! ______________________________________________________________

! _______________________________________________________________________

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Magma / Intrusive

Lava / ExtrusivePlutonic Rock

Volcanic Rock


2. Color - ! _______________________________________________________________________

! ______________________________________________________________________________

3. Composition - a mixture of materials that make up an igneous rock

• Felsic -! _________________________________________________________________

! _______________________________________________________________________

• Mafic -! __________________________________________________________________

! _______________________________________________________________________

4. Texture - ! ______________________________________________________________________

! ______________________________________________________________________________

• Vesicular - ! ______________________________________________________________

! _______________________________________________________________________

• Porphyritic - ! ____________________________________________________________

! _______________________________________________________________________

5. Crystal Size - ! __________________________________________________________________

! ______________________________________________________________________________

• Crystal size is an important factor to determine the environment of formation

• The _______________ the cooling time the _______________ the crystal size (coarse or very coarse)

• The _______________ the cooling time the _______________ the crystal size (glassy or fine)

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Fine Grained Coarse Grained


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Scheme for Igneous Rock Identification

Pyroxene(green)

Amphibole(black)

Biotite(black)

Potassiumfeldspar

(pink to white)

(rel

ativ

e by

vol

ume)

MIN

ER

AL

CO

MP

OS

ITIO

N

Quartz(clear towhite)

CH

AR

AC

TE

RIS

TIC

S

MAFIC(rich in Fe, Mg)

HIGHER

DARKER

FELSIC(rich in Si, Al)

LOWER

LIGHTER

CRYSTALSIZE

TEXTURE

Pumice

INT

RU

SIV

E(P

luto

nic)

EX

TR

US

IVE

(Vol

cani

c)

EN

VIR

ON

ME

NT

OF

FO

RM

AT

ION

Plagioclase feldspar(white to gray)

Olivine(green)

COMPOSITION

DENSITY

COLOR

100%

75%

50%

25%

0%

100%

75%

50%

25%

0%

IGN

EO

US

RO

CK

S

non-

crys

talli

ne

GlassyBasaltic glassObsidian

(usually appears black)

less

than

1 m

m FineBasaltAndesiteRhyolite

1 m

mto

10

mm

CoarsePeri-dotiteGabbro

DioriteGranite

Pegmatite

10 m

mor

larg

er Verycoarse

Scoria Vesicular(gas

pockets)

Du

nit

e

Non-vesicular

Non-vesicular

Vesicular basaltVesicular rhyolite Vesicularandesite

Diabase


III. Sedimentary Rocks

• Sedimentary Rocks - ! __________________________________________________________________

! _____________________________________________________________________________________

• Lithification - ! _________________________________________________________________________

! _____________________________________________________________________________________

• Methods to classify sedimentary rocks:

1. Texture - ! _____________________________________________________________________

! ______________________________________________________________________________

• Texture is the main factor in sedimentary rock identification

• Clastic - ! _________________________________________________________

! _________________________________________________________________

• Crystalline - ! ______________________________________________________

! _________________________________________________________________

• Bioclastic - ! _______________________________________________________

! _________________________________________________________________

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Bioclastic Contains Shell Fragments


• Methods to classify sedimentary rocks (continued):

2. Formation - ! ___________________________________________________________________

! ______________________________________________________________________________

• Most sedimentary rocks form under large bodies of water by the following:

• Cementation - ! ____________________________________________________

! _________________________________________________________________

• Occurs as water between sediments dissolves and the remaining materials hold the clasts together

• Compaction - ! _____________________________________________________

! _________________________________________________________________

• Usually results in a decrease in pore space and sediments become more tightly packs

• Chemical Action - ! _________________________________________________

! _________________________________________________________________

3. Characteristics - ! _______________________________________________________________

! ______________________________________________________________________________

• Form at or near Earth’s surface where weathering can break down rocks into pieces

• Forms in horizontal layers

• May contain fossils

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Horizontal Layers

Fossils


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INORGANIC LAND-DERIVED SEDIMENTARY ROCKS

COMPOSITIONTEXTURE GRAIN SIZE COMMENTS ROCK NAME MAP SYMBOL

Rounded fragments

Angular fragmentsMostlyquartz,feldspar, andclay minerals;may containfragments ofother rocksand minerals

Pebbles, cobbles,and/or bouldersembedded in sand,silt, and/or clay

Clastic(fragmental)

Very fine grain

Compact; may spliteasily

Conglomerate

Breccia

CHEMICALLY AND/OR ORGANICALLY FORMED SEDIMENTARY ROCKS

Crystalline

Halite

Gypsum

Dolomite

Calcite

Carbon

Crystals fromchemicalprecipitatesand evaporites

Rock salt

Rock gypsum

Dolostone

Limestone

Bituminous coal

. . . . .. . . .

Sand(0.006 to 0.2 cm)

Silt(0.0004 to 0.006 cm)

Clay(less than 0.0004 cm)

Sandstone

Siltstone

Shale

Fine to coarse

COMPOSITIONTEXTURE GRAIN SIZE COMMENTS ROCK NAME MAP SYMBOL

Fineto

coarsecrystals

Microscopic tovery coarse

Precipitates of biologicorigin or cemented shellfragments

Compactedplant remains

. . . . .. . . .

Bioclastic

Crystalline orbioclastic

Scheme for Sedimentary Rock Identification


IV. Metamorphic Rocks

• Metamorphic Rocks - ! _________________________________________________________________

! _____________________________________________________________________________________

• Parent Rock - ! ________________________________________________________________________

! _____________________________________________________________________________________

• Heat

• Rock expands when heated causing the atoms to break apart and move freely

• As temperature decreases atoms join with other atoms to form different compounds

• The result is a structural and chemical change

• Pressure

• Under extreme pressure at great depths inside the Earth, atoms bonds are broken and re-arranged into a denser and more compact structure

• Methods to classify metamorphic rocks:

1. Texture - the general appearance of the rock

• Foliation -! _______________________________________________________________

! _______________________________________________________________________

• Banding -! _______________________________________________________________

! _______________________________________________________________________

• Non-foliated -! ____________________________________________________________

! _______________________________________________________________________

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Foliated Banding Non-foliated


• Methods to classify metamorphic rocks (continued):

2. Grain Size - ! ___________________________________________________________________

! ______________________________________________________________________________

3. Composition- ! __________________________________________________________________

! ______________________________________________________________________________

4. Type of Metamorphism-

• Regional Metamorphism -! _________________________________________________

! _______________________________________________________________________

• Most metamorphic rocks form regionally under a mountain or deep in-side the Earth

• Contact Metamorphism -! __________________________________________________

! _______________________________________________________________________

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FO

LIA

TE

D

Fine

Fineto

medium

Mediumto

coarse

Regional

Low-grademetamorphism of shale

Platy mica crystals visiblefrom metamorphism of clayor feldspars

High-grade metamorphism;mineral types segregatedinto bands

Slate

Schist

Gneiss

COMPOSITIONTEXTUREGRAINSIZE COMMENTS ROCK NAME

TYPE OFMETAMORPHISM

(Heat andpressureincreases)

MIN

ER

AL

ALI

GN

ME

NT

BA

ND

-IN

G

MAP SYMBOL

Foliation surfaces shinyfrom microscopic micacrystals

Phyllite

GA

RN

ET

PY

RO

XE

NE

FE

LD

SPA

R

AM

PH

IBO

LE

MIC

AQ

UA

RT

Z

Hornfels

NO

NF

OLI

AT

ED

Metamorphism ofquartz sandstone

Metamorphism oflimestone or dolostone

Pebbles may be distortedor stretched

Metaconglomerate

Quartzite

Marble

Coarse

Fineto

coarse

Quartz

Calcite and/ordolomite

Variousminerals

Contact(heat)

Various rocks changed byheat from nearbymagma/lava

VariousmineralsFine

Anthracite coalRegional Metamorphism ofbituminous coalCarbonFine

Regional

or

contact

Scheme for Metamorphic Rock Identification


V. Rock Cycle

• Rock Cycle - ! _________________________________________________________________________

! _____________________________________________________________________________________

• Any rock type can change into another rock type

• Therefore any rock could contain materials that were one part of another rock

• Igneous Rock - ! _______________________________________________________________________

! _____________________________________________________________________________________

• Sedimentary Rock - ! ___________________________________________________________________

! _____________________________________________________________________________________

• Metamorphic Rock - ! __________________________________________________________________

! _____________________________________________________________________________________

• Driving Forces - the processes that create uplift, weathering, erosion, pressure, and melting to form the different rock types

• ______________________________________________

• ______________________________________________

• ______________________________________________

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Class Notes: Minerals and Rocks - Earth...

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