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Earth Science, 6e
Edward J. Tarbuck & Frederick K. Lutgens
Minerals, What for?
Do we need Minerals?
Name a few things made of minerals:
Example: Glass is made from…
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 rock-forming minerals (see page 35)
The eight elements that compose most rock-forming 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
• “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 hasa: 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 showa: 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. Luster
b. Hardness
c. Streak
d. Reaction to Hydrochloric Acid
e. None of these
9 - One of these minerals is a Sulfide
a. Calcite (CaCO3)
b. Quartz (SiO2)
c. Gypsum (CaSO4.H2O)
d. Pyrite (FeS2)
e. None of the above
10 - Which term does not define a mineral?
a. Natural
b. Solid
c. Organic
d. Definite crystalline structure
e. Definite Chemical Composition
11 - Which mineral has double refraction, hardness =3, and
reacts with hydrochloric acid?
a. Pyrite
b. Galena
c. Quartz
d. Calcite
e. None of these
THE END
THAT’S ALL FOLKS!
THANK YOU!!!