Transcript Chapter 3 Notes PowerPoint

Ch 3 Minerals
Worlds largest diamond mine
Layers of the Earth
Crust (8 to 32 km)
Mantle (2900 km)
Liquid Core(2250 km)
Solid Core (1300 km)
Core
1. Solid Inner Core:
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Made of solid Nickel and Iron
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Under great pressure resulting in a solid form.
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Iron causes the Earth to be
magnetic
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5000 degrees Celsius
2. Liquid Outer Core
Made of liquid Nickel and Iron
2200 degrees Celsius
Mantle
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Molten, liquid rock (Magma)
Makes up about 80% of Earth’s
volume
Ranges from 870 to 2200 degrees
Celsius
Crust and Mantle divided by the
Moho Boundary
Crust
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Very thin, solid layer of rock
Made of mostly Silicon &
Oxygen (75%)
What are Minerals?
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Naturally occurring –
not man-made, in the earth
Inorganic –
doesn’t come from living things
Always a solid –
has volume and shape
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Definite chemical composition –
made of a single pure
substance or element
Crystalline form –
flat sides, sharp edges &
corners
Formation & Composition
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As hot magma cools, the
minerals will crystallize.
If the magma cools very slowly it
forms large crystals. If it cools
very quickly it forms tiny to
microscopic crystals.
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Some mineral crystals will form
compounds dissolved in
liquids. Minerals will be left
behind when the liquid
evaporates.
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The eight most common elements
in the crust form a large number of
the known minerals.
(O, Si, Al, Fe, Ca, Na, K, & Mg)
The compound formed by Silicon &
Oxygen is known as Silicate.
Mineral Identification
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The identification of a
mineral is based on its
physical properties
1. Color
• Some minerals have characteristic
colors
• Some minerals can come in several
different color varieties
EX: Quartz & Corundum
Some of the colors can change due to
temperature, pollution, or radiation.
2. Luster
The way a mineral reflects light
off its surface.
• 2 types
A. Metallic – very shiny, looks like a metal
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B. Non-metallic Glassy – shiny, transparent, translucent
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Earthy - clay-like, dull
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Pearly: pearl-like
3. Hardness
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The ability for a mineral to
resist being scratched.
Mohs Hardness Scale
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A list of ten minerals ranked
according to hardness.
1= softest (talc)
10=hardest (diamond)
1. Talc
5. Apatite
2. Gypsum
6. Feldspar
9. Corundum
3. Calcite
7. Quartz
4. Fluorite
8. Topaz
10. Diamond
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A mineral that is higher on the scale
will scratch the mineral that is lower.
Other common items have been given
ratings on the scale for identification
purposes.
EX: Fingernail, Penny, File, Glass
4. Streak
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The color of the powder scraped off a
mineral when rubbed against a rough
surface (streak plate.)
Very useful property for showing the TRUE
color.
Same color always, no matter what the
variation
5. Breakage
2 types –
a. Cleavage - breaks in smooth, definite
surfaces
• Same every time
b. Fracture - breaks in rough or jagged
surfaces
6. Crystal Form
• Geometric crystals with
flat surfaces and definite
edges
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Cubic
Hexagonal
Tetragonal
Orthorhombic
Monoclinic
Triclinic
• Different from cleavage
7. Other Properties
1.
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Reaction to Acid some minerals will bubble
in acid
Magnetism some special minerals
will be magnetic
Sulfur
Smell some will have distinct odors
Taste some have a distinct taste
Halite
Calcite
Mineral Groups
1. Silicates
• Most common mineral family
• Silicon-oxygen tetrahedron (SiO4)
along with additional elements.
• Joined together into chains, sheets,
or 3-demensional networks.
EXAMPLES: Feldspars, Quartz, Micas
2. Carbonates
• Carbonates are used in cement & lime.
• Made of Carbonate (CO3) with other
elements.
EXAMPLES: Calcite & Dolomite
3. Halides
• Used in steel making, fertilizer, & salt
EXAMPLES: Halite & Fluorite
4. Sulfates
• Used in plaster.
• Made of Sulfate (SO4) with other
elements.
EXAMPLE: Gypsum
5. Oxides
• Have Oxygen as a major component.
EXAMPLES: Hematite, Magnetite,
Corundum, & Ice
6. Native Elements
• Minerals of great economic value that
are pure elements.
EXAMPLES: Gold, Silver, Diamond (C),
Sulfur, Graphite (C), Copper,
Platinum
Uses for Minerals
1. Ores
Minerals or combinations of minerals from
which metals and nonmetals can be
removed in usable amounts.
Examples: Cinnabar (Mercury),
Bauxite (Aluminum),
Hematite (Iron)
• Smelting- when an ore is heated so that
a metal can be separated from it.
• Alloys- when pure metals are combined
to form other metallic substances.
(Steel
& Brass)
2. Gemstones
• Minerals that are hard,
beautiful, and durable.
• They are substances that can
be cut & polished for jewelry &
decoration.
a. Precious Stones
• The rarest & most valuable.
Ex: Diamonds, Rubies, Opals,
Sapphires, & Emeralds
b. Semiprecious Stones
• The other gemstones
Ex: Amethysts, Zircons, Garnets,
Turquoises, Jades, & more
c. Non-Mineral Gemstones
• Come from living things
Ex: Amber, Pearls, & Coral