Earth Science, 6e
Edward J. Tarbuck &
Frederick K. Lutgens
Minerals, What for?
 Do we need Minerals?
Name a few things made from minerals:
Example: Glass is made from…
• Steel
• Pencil lead
• Bullets
• Sheet rock
Structure of an Atom
How atoms are constructed
Atomic number or atom’s electrical
charge: number of protons of the atom
 Atomic mass number or atomic weight:
Neutrons plus protons
Atomic Bonding
Atomic Bonds
 Ionic Bonds: Electron Transfer
 Covalent Bonds: Electrons sharing
 Metallic Bonds: Free electrons
Ions: Atoms that gain or lose electrons
Isotopes Same atom with a different weight
Minerals: the building
blocks of rocks
Definition of a mineral
•
•
•
•
•
Natural
Inorganic
Solid
Possess an orderly internal structure of atoms
Have a definite chemical composition
Mineraloid - lacks an orderly internal
structure
Minerals
Physical properties of minerals
•
•
•
•
•
•
Crystal form
Luster
Color
Streak
Hardness versus Tenacity
Cleavage (breaks evenly)
The mineral quartz often
exhibits good crystal form
Pyrite (fool’s gold)
displays metallic luster
Color, not reliable…
Three examples of perfect
cleavage – fluorite, halite,
and calcite
Conchoidal fracture
Minerals
Physical properties of minerals
• Fracture (breaks unevenly)
• Specific gravity (mineral heftiness)
• Other properties
• Taste
• Smell
Minerals
Physical properties of minerals
• Other properties
•
•
•
•
Feel
Magnetism
Double Refraction
Reaction to hydrochloric acid
Minerals
A few dozen minerals are called the rockforming minerals (see page 35)
The eight elements that compose most rockforming minerals are (see page 34)
Minerals
Silicates Minerals (see page 35)
Most common mineral group (90% of minerals)
• Contain the silicon-oxygen tetrahedron
• Four oxygen atoms surrounding a much smaller
silicon atom
• Combines with other atoms to form the various
silicate structures
The silicate (SiO4)-4 molecule
Common silicate minerals
Potassium feldspar
Minerals
 Nonsilicate Minerals ( see page 36)
• Major groups
• Oxides
• Sulfides
• Sulfates
• Carbonates
• Halides
• “Native” elements
Native Copper
Some common non-silicate
minerals
An underground halite (salt) mine
The Bingham copper
mine in Utah
End of Chapter 1
PRS Test on Minerals
Please do not talk to your
neighbor during the test.
Thank you.
1- This silicate (SiO4)-4 molecule has
a: 1 silicon 4 oxygen; or b:1 oxygen 4
silicon
2 - Does this quartz mineral show
a: Cleavage faces or b: Crystal form?
3 - What is the luster displayed by this
mineral ?
a: metallic; b: non metallic
4 - Do these minerals have
a: perfect cleavage;
b: absence of cleavage
5 - Does this mineral show
a: good cleavage or
b: conchoidal fracture?
6 - What mineral is this?
a: Calcite or b: Potassium Feldspar
7 - What are the two minerals
your fingernail can scratch?
a. Calcite and Gypsum
b. Gypsum and Talc
c. Talc and Calcite
8 - The most reliable way to
identify a carbonate mineral is by
a.
b.
c.
d.
e.
Luster
Hardness
Streak
Reaction to Hydrochloric Acid
None of these
9 - One of these minerals is a
Sulfide
a.
b.
c.
d.
e.
Calcite (CaCO3)
Quartz (SiO2)
Gypsum (CaSO4.H2O)
Pyrite (FeS2)
None of the above
10 - Which term does not
define a mineral?
a.
b.
c.
d.
e.
Natural
Solid
Organic
Definite crystalline structure
Definite Chemical Composition
11 - Which mineral has double
refraction, hardness =3, and
reacts with hydrochloric acid?
a.
b.
c.
d.
e.
Pyrite
Galena
Quartz
Calcite
None of these
THE END
THAT’S ALL FOLKS!
THANK YOU!!!