I. Lecture Content
- Topics
Matter and Its Physical
States
Elements, Atoms, and Isotopes
Chemical Bonding and
Compounds
Crystals and Minerals
Defining a Mineral
Classification of Minerals
The Silicate Mineral Group
The Carbonate Mineral Group
Other Mineral Groups
Mineral Identification
Focus on The Major
Rock-Forming Minerals
Mineral Resources and
Reserves
II.
Physical States of Matter
A. Definition of Matter
1. Anything that has mass and occupies space
· Atoms and molecules
· All Earth materials
2. The intimate relationship
between matter and energy
· Einstein's famous equation -
E = mc2
B. The Four Different States of Matter
1. Solid
2. Liquid
3. Gas
4. Plasma
C. Transformation of Matter from One
State to Another
1. Also called a "phase
change"
2. Always involves a condition change in the system
3. Change in physical state
always involves a process
4. Many major Earth
processes involves a phase change
III. Elements, Atoms and Isotopes
A. Elements: Basic Building Blocks of
Earth Materials
1. There are 92 naturally
occurring elements on Earth
·
Most
created in (an) ancient star(s)
·
Each
element has a name and a symbol
·
Organized
in the Periodic Table of Elements
·
Range
in mass from Hydrogen to Uranium
2. Most Common Elements in Earth's Crust
ü Oxygen (63%)
ü Silicon (28%)
ü Aluminum (8%)
ü Iron (5%)
ü Calcium (4%)
ü Sodium (3%)
ü Potassium (3%)
ü Magnesium (2%)
2. Elements are composed of tiny particles called
atoms
·
Smallest
units of matter that characterize elements
·
Atoms
are composed of even smaller particles
3. Atoms have an organized internal structure
·
Center
of atom consists of nucleus (positively-charges protons and neutral neutrons)
·
Outer
part of atoms consists of a "cloud" of negatively-charged electrons
4. Number of protons in an
atom = the type of element
·
Called
the atomic number
5. The sum of protons and neutrons in an atom determines
the element's atomic mass
· Called the
atomic mass number
6. Atoms of a single element can vary in atomic mass
· Proton # same; Variation in
neutron #
· Called "isotopes"
· Most isotopes are stable;
some are unstable
IV. Chemical Bonding, Molecules &
Compounds
A. Bonding of Atoms into Molecules &
Compounds
1. Molecule defined:
A substance made up of two or more
atoms
that are bonded together
2. Compound defined:
A substance made up of atoms from
two or
more elements that are bonded together
3. Ions defined: are
atoms, molecules, or compounds that
have
either, more, or less electrons (-) than the
number of protons (+)
· Ions possess an electrical
charge (+ or -)
· Compounds that are ions are called
radicals
4. Bonding defined:
The process of joining together two
or more
atoms into molecules or compounds
5. Bonding
is caused by the interaction of the electron
clouds
between closely adjoining atoms and/or
molecules
5. Two major types of chemical
bonding
· Ionic
· Covalent
6. Two other types of chemical bonding
· Metallic
· Van der Waal
B. Ionic Bonding
1. The formation of a compound by the
electromagnetic
attraction
of oppositely-charged ionic substances
· Involves the transfer of
electron(s)
· Example: Halite (sodium
chloride)
2. Neutral ionic compounds are
called salts and consist of
a pair of ions
· Cation (positively-charged
ion)
· Anion (negatively-charged
ion)
3. Ionic
bonds are relatively weak (easily broken)
C. Covalent Bonding
1. The formation of a molecule or compound by
the sharing
of the outermost
electrons between atoms
· Examples:
ü
Diamond
(C-pure carbon)
ü
Silica
radical (SiO4)-4
ü
Carbonate
radical (CaCO3)-2
2. Covalent bonds are relatively strong compared to
ionic
3. Minerals consist of compounds that typically have
both
ionic
and covalent bonds
V. Crystals and Minerals
A. Crystalline Substances
1. Crystals are highly-ordered,
solid substances having a
regular,
three-dimensional framework
· Ordered internal atomic
arrangement
· Unit structures are of
atomic scale
2. When completely unimpeded, crystals will grow
with into
perfect
geometric forms, that reflect their unit structure
3. Not all solid, rigid substances are crystalline
· Called amorphous - lack
crystal structure
· Examples are glass, obsidian
& opal
B. Mineral - Defined
1.
Naturally occurring
2.
Inorganic
3.
Crystalline solid
4.
Narrowly defined chemical composition
5.
Characteristic physical properties
C. Over 3,500 Different
Minerals Have Been Recognized
Ø
See Mineral Glossary on Teacher's Web Page
VI. Classification of Minerals into Groups
A. The Silicate Group
1.
Characteristics of the Silicate Group
·
Base
compound is the silica radical (SiO4)-4
·
Basic
structure is the silica tetrahedron
· Vast majority of
rock-forming minerals found in the crust and mantle belong to the silicate
group
2. The Silicate Group has several subgroups that are
based
on
their arrangement of silica tetrahedral:
· Olivine Group
· Pyroxene Group
· Amphibole Group
· Mica Group
· Clay Mineral Group
· Quartz Group
3. The
Silicate Group can also be divided into two groups
based
on chemical composition
· The Ferromagnesian Silicates
ü Olivine
ü Pyroxenes
ü Amphiboles
ü Dark-colored Micas
· The Nonferromagnesian
Silicates
ü Quartz
ü Plagioclase feldspar
ü Potassium feldspar
ü "White" micas
4. Silicate group minerals form primarily in igneous
and
metamorphic
rocks, but are also present as detritus
in
sedimentary rock and sediments.
5. Hand samples of the different silicate subgroups:
B. The Carbonate Group
1. Characteristics of the
Carbonate Group
· Base compound is carbonate
radical (CaCO3)-2
· Carbonate minerals are
restricted to the crust
2. Carbonate
minerals form mainly form in sedimentary
and
metamorphic rocks
3. Most typical carbonate
minerals are calcite, aragonite,
and dolomite.
4. Hand samples of carbonate
minerals
D. Other Mineral Groups
1.
The Oxide Group
2. The Sulphide Group
3. The Halide Group
4. The Sulphate Group
VII. Mineralization Processes
A. Minerals Can Grow in Various Environments
1.
Crystallization from magma and lavas
· Igneous mineralization
2.
Crystallization from an aqueous solution
· Hydrothermal mineralization
· Sedimentary mineralization
3.
Neo-crystallization and re-crystallization in the solid stat
· Metamorphic mineralization
VIII. Identification of Minerals
A. Physical and Chemical Properties of
Minerals
1.
Luster & Color
2.
Cleavage & Fracture
3.
Hardness
4. Crystal Class
5. Mineral Habit
6. Density (specific
gravity)
7. Reaction to acid
8. Magnetic susceptibility
9. Reaction to ultraviolet
light
10. Radioactivity
11. Taste
B. Optical Properties of Minerals
1. Refraction of polarized light
through minerals
·
Each
mineral has a unique light refraction value
·
Based
on both crystal structure & composition
C. Atomic Properties of Minerals
1. Interaction of X-rays and
mineral crystals
·
Each
mineral has a unique X-ray pattern
·
Based
on both crystal structure & composition
D. Techniques Used for Identifying Minerals
1. Hand
sample (bare eye) identification
2.
"Blowpipe" flame-jet technique
3.
Polarizing microscope
4.
Atomic absorption
5.
Electron-beam microprobe
6.
X-ray diffraction or fluorescence
7.
Nuclear (neutron activation)
IX. The Major Rock-Forming Minerals
A. Rock defined:
1. An aggregate of crystals
consisting of one or more
mineral species
2. Two exceptions are obsidian
(natural glass) and coal
B. Only About a Dozen Major
Rock-Forming Minerals
Form the Bulk of Earth's
Lithosphere
Ferromagnesian Silicates (mainly igneous &
metamorphic)
1. Olivine
- (Mg, Fe)2SiO4
2. Pyroxene group - Ca, Mg, Fe, Al-silicate
·
Augite
species most common
3. Amphibole group - H2O, Na, Ca, Mg, Fe,
Al-silicate
·
Hornblende
species most common
4. Biotite
- hydrous K, Mg, Fe, Al-silicate
Nonferromagnesian Silicates (all three rock types)
5. Quartz
- SiO2
6. Potassium
feldspar - KalSi3O8
·
Orthoclase
& Microcline most common
7. Plagioclase
feldspar group -
·
Varies
from CaAl2Si2O8 to NaAlSi3O8
8. Muscovite
- hydrous K, Al silicate
9. Clay
group - variable hydrous Al silicate
Carbonates (sedimentary & metamorphic rocks)
10. Calcite
- CaCO3
11. Dolomite
- CaMg(CO3) 2
Sulphates (exclusively sedimentary rocks)
12. Anhydrate - CaSO4
13. Gypsum
- CaSO4 . 2H2O
Halides (exclusively sedimentary rocks)
14. Halite
- NaCl
Oxides (all rock types)
15.
Magnetite - Fe3O4
16.
Hematite - Fe2O3
17.
Limonite - hydrated iron oxide
Sulfides
(all rock types)
18.
Pyrite - FeS2
19.
Galena - PbS
20.
Chalcopyrite - CuFeS2
21. Sphalerite - (Zn,
Fe)S
X. Mineral Resources and Reserves
A. Resource & Reserve defined by the U.S.G.S
1. Resource:
A concentration of naturally
occurring solid, liquid,
or
gaseous material in or on the Earth's crust in such
a
form and amount that economic extraction of a
commodity
from the concentration is currently or
potentially
feasible.
2. Reserve:
That part of a resource base that can be currently
economically extracted (given today's market price)
B. Factors That Define a Resource From a Reserve
1. Total abundance of mineral
2. Degree of concentration of a mineral
3. Geographic location
4. Political location
5. Market commodity price
6. Technological expertise
7. New markets and uses
C. Nonfuel Mineral Production in the United States
1.
Compare Figures in Table 2.8
2.
About $40 billion a year in mineral commodities extracted
from
U.S. mines
3. The
major mineral commodities extracted in the U.S
· Sand and gravel
· Cement
· Crushed stone
· Gold
· Copper
· Silver
· Iron ore
· Lead
· Magnesium metal
· Boron
· Phosphate rock
· Clays
D. Interesting Fact about Metal Resources
· About 75% of all metals
mined in the world come
from about only 150 locations
E. Virtually All Mineral Resources are Nonrenewable
· World's richest deposits
have already been mined
XI. Vocabulary Terms
Amphibole
Atom
Atomic
mass number
Atomic
number
Biotite
Bonding
Calcite
Carbonate
mineral
Cleavage
Compound
Covalent
bond
Crystalline
solid
Dolomite
Electron
Electron
cloud
Element
Ferromagnesian
silicate
Gypsum
Halide
Hardness
Ion
Ionic
bond
Luster
Mineral
Muscovite
Native
element
Neutron
Nonferromagnesian
silicate
Nucleus
Olivine
Potassium
feldspar
Plagioclase
feldspar
Proton
Pyroxene
Quartz
Reserve
Resource
Rock
Rock-forming
mineral
Silica
Silica
tetrahedron
Silicate