Download Minerals

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Which rocks are made from sediment?
Which rocks are made from magma?
Which rock type can make
metamorphic rock?
What are rocks made of?
Minerals
Objective(s):
Distinguish between elemental and
compound minerals
List the criteria for being considered a mineral
List the physical and chemical properties used
to identify minerals
Atoms
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Building blocks for all materials on
Earth
– 3 components:
• Protons
• Neutrons
• Electrons
Elements
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Atoms combine to form elements
– Can’t be broken down by chemical means
Minerals
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Elements combine to form MINERALS
Atoms
Elements
Minerals
Mineral Criteria
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Naturally Occurring
– Not man-made
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Inorganic
– Not made from living things or the remains of
them
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Solid
– Definite size and shape
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Definite Chemical Composition
– Quartz = SiO2
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Crystalline Structure
– Atoms arranged in repeating patterns
A Mineral is Born – 2 Ways
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The cooling of magma.
– As magma cools, atoms migrate together and form
different compounds.
The slower magma cools, the larger the crystal formation
 The faster magma cools, the smaller the crystal
formation.
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Slow cooling = Large
crystals
Fast cooling = Small crystals
A Mineral is Born – 2 Ways
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Minerals can precipitate out of a solution
– When water is saturated with dissolved solids and
can’t hold any more, the extra falls out of the
solution.
Saturated Solution
Salt Water – Salt is completely dissolved
Salt Water – Salt particles are floating
Water can’t hold anymore salt, the extra
settles to the bottom
Mineral Composition
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Elemental
– Composed of only 1 element
Graphite (C)
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Copper (Cu)
Gold (Au)
Diamond (C)
Compound
– Composed of 2 or more elements
Identifying Minerals
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Mineral Properties are determined by
their “internal arrangement of atoms”
Different Arrangements
=
Different Properties
Graphite
Diamond
BOTH ARE MADE
OF CARBON!
Do Now
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List each type of rock and describe
properties of each.
Take out the lab from last Thursday.
Describe the rock cycle.
DO NOW
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What criteria defines a mineral?
Naturally occurring
Inorganic
Solid
Definite chemical composition
Crystalline structure
Mineral Properties
Physical Properties
1.
2.
3.
4.
5.
6.
Color
Streak
Luster
Hardness
Cleavage/Fracture
Density
Chemical Properties
1. Magnetism
2. Reaction to Acid
Physical Properties
1. COLOR
– Most visible property of a mineral
Unreliable when used
alone!!!
Why?
One mineral can have many colors
Different minerals have similar colors
Colors of Quartz
2. STREAK
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Color of a mineral in its powder form
STREAK MAY BE DIFFERENT
THAN THE MINERAL COLOR
Varieties of Hematite
– all same color streak
3. LUSTER
 How light is reflected off of the surface of
a mineral
 Two types
– Metallic
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Shines like brightly polished METAL
– Non-metallic
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Glassy, dull, earthy, pearly
Examples of Metallic Luster
GALENA
PYRITE
GRAPHITE
Examples of Non-Metallic
Luster
QUARTZ
FELDSPAR
4. HARDNESS
 The resistance ability of a mineral
when scratched
THE SOFTER THE MINERAL, THE
EASIER IT IS TO SCRATCH
Higher numbers will
scratch lower numbers
Physical Properties
5. CLEAVAGE AND FRACTURE
 Cleavage
– Breaks in a pattern
 Fracture
– Splits unevenly into irregular pieces with
rough and jagged edges
Cleavage – due to weak bonds
in the crystal structure
Halite (NaCl)
Fluorite (CaF2)
HALITE
FLUORITE
MUSCOVITE
BIOTITE
Rose Quartz –Fracture
Fracture - Quartz
Obsidian
Chemical Properties
1.
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MAGNETISM
Magnetic elements found within
magnetite
– Ex – Iron (Fe) in Magnetite
2. Fizzing with HCl (Hydrochloric
Acid)
 Some minerals react with acid to
form bubbles
– Ex – Calcite and Dolomite
CAN TELL THE DIFFERENCE BETWEEN
HALITE AND CALCITE
The diagram below shows a method for determining a
physical property of a mineral. The results are shown
for two minerals, galena and
calcite.
Which property of the galena and calcite is indicated by
the color of the powder each leaves on the ceramic tile?
(1) streak
(2) hardness
(3) reaction to an acid
(4) reaction to a solvent
The diagram below shows a penny scratching the surface
of the mineral calcite. Which physical property of the
calcite is being tested?
(1) streak (3) melting point
(2) hardness (4) reaction to acid
A chemical property of a mineral is evident if the
mineral
(1)
(2)
(3)
(4)
breaks easily when struck with a hammer
bubbles when acid is placed on it
is easily scratched by a fingernail
reflects light from its surface