Transcript 37 Rock Cycle2

The
Rock Cycle
Elements in the
Earth’s ATMOSPHERE
Element
Amount
Nitrogen
78.1 %
Oxygen
20.9 %
Argon
0.96 %
Elements in the
Earth’s OCEANS
Element
Amount
Oxygen
85.84 %
Hydrogen
10.82 %
Chlorine
1.94 %
Sodium
1.08 %
Magnesium
0.1292 %
Elements in the
Earth’s CRUST
Element
Amount
Oxygen
47 %
Silicon
28.2 %
Aluminum
8.23 %
Iron
5.63 %
Calcium
3.5 %
IGNEOUS ROCKS
• Forms from cooled lava.
• Most have crystals… the size of the crystal
depends on how fast the lava cooled.
- Slow cooling = large crystals
- Fast cooling = small to microscopic
• Some rocks have pores (like a sponge) from the
gases in the lava escaping during the cooling
process.
Uses of Igneous Rocks
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Road building materials
Gravestones
Creating lasting monuments
Used as an abrasive in polish things.
For trim and decoration in buildings.
Decorative landscape stone.
Jewelry
IGNEOUS ROCKS
Granite
Pumice
Obsidian
Gabbro
Igneous rock forms in
two ways!
Intrusive
Extrusive
- Forms from magma
cooling and solidifying
inside the earth’s
crust.
- Forms from lava
cooling and solidifying
outside of the earth’s
crust.
SEDIMENTARY ROCKS
• Formed from weathered igneous and
metamorphic rocks that are compacted
and cemented together!
• Usually layers can be seen.
• Some are conglomerates… i.e. you can
see smaller rocks or shells embedded.
Uses of
Sedimentary Rocks
• Gypsum is used to make plaster of Paris
and in drywall.
• Sandstone and limestone are used as
building stones.
• Limestone is also used for hard core
cement roads.
SEDIMENTARY ROCKS
Conglomerate
Limestone
Shale
Banded-Sandstone
METAMORPHIC ROCKS
Formed within the Earth… rocks that
undergo an extreme amount of heat
and pressure.
These rocks are usually very dense
rocks.
Uses of
Metamorphic Rocks
• Used for pool table tops
• Carved into statues
• Buildings materials (floor tiles roofing
tiles and counter tops)
• Jewelry = Diamonds
METAMORPHIC ROCKS
Marble
Mica Schist
Slate
Quartzite
Rock Cycle
The Importance of
Rocks and Minerals
Igneous
Obsidian
Used in making arrowheads and knives
Basalt
Used in road building materials
Pumice
Used in scouring, scrubbing, and polishing
materials
Granite
Used for buildings, monuments, and
tombstones
The Importance of
Rocks and Minerals
Sedimentary
Sandstone
Used in the building industry for houses
Gypsum (mineral)
is used to make plaster of Paris and in
drywall
Limestone
is also used for hard core cement roads.
The Importance of
Rocks and Minerals
Metamorphic
Marble
Used in building, floors, tile in
bathrooms
Slate
Used for
roofs, chalkboards, patio walks and pool
tables
The Importance of
Rocks and Minerals
Minerals
Calcite
Used in cements and mortars and the
production of lime
Quartz
Used in making glass, electrical
components, and optical lenses
Physical
Properties of
Rocks and
Minerals
Minerals
A mineral is…
• Naturally occurring
• Inorganic- (made up of none living things)
• Definite chemical composition & crystal
structure
• Solid
All physical properties of minerals come
from the “internal arrangement of atoms”
Mineral Identification
Tests
• The Streak Test
• The Color Test
• The Luster Test
• Hardness (Moh’s
Scale)
• Cleavage
• Crystal Shape
• Reactions with Acids
• Specific gravity
The Streak Test
• The color of the powdered mineral
performed by rubbing the unknown
mineral on an unglazed tile.
The Luster Test
• The way a mineral shines or doesn't shine
• The only way to really learn the different luster's
is to see them for yourself.
• 2 Types of Luster
• Metallic and Non-Metallic
• Metallic Luster
Rocks look
like shiny metal
• Ex. Hematite
Non-Metallic Luster
• Non-metallic- all the other ways that a mineral can
shine
– Glassy- shines like a piece of broken glass
(most common non-metallic)
– Dull/earthy- no shine at all
– Resinous/waxy- looks like a piece of plastic or
dried glue
– Pearly- looks oily it may have a slight rainbow
like an oil slick on water. Also looks like the
inside of some clam shells
– Adamantine- brilliant, sparkling shine like a
Color Test
• Color is used to determine the
type of rock but it is not always
reliable.
• Sulfur is (almost) always yellow,
and there are a few others, but
not many minerals have a fixed
color. Small amounts of impurities
can drastically change a mineral's
Hardness Test
• Hardness- a minerals resistance
to scratching.
• This should not be confused with
brittleness. A diamond is very
hard and will scratch a hammer
but a hammer will smash a
diamond.
Moh’s Scale of Hardness
• Talc (Softest)
• Gypsum
• Calcite
• Fluorite
• Apatite
• Feldspar (AKA Albite)
• Quartz
• Topaz
• Corundum
• Diamond (Hardest)
Cleavage Test
• Cleavage –The rocks
will break along flat
surfaces or…
• Cubic- Rocks will
break into cubes.
Crystal Formation
• Minerals will grow
crystal formations
when given time &
space to grow.
• Can be recognized by
their beautiful regular
shapes once you
have seen a few
examples.
Quartz Crystal
Formation
Miscellaneous Tests
• Acid- Calcite and powdered dolomite will
Effervescence (fizz) in diluted
hydrochloric acid (HCl)
• Smell- Sphalerite will give off a rotten-egg
smell when streaked on a streak plate.
Magnetism- Magnetite (AKA Lodestone)
will pick up paper clips
Miscellaneous Tests
Cont.
• Taste- Halite is rock salt and will taste
salty.
• Fluorescence- some minerals (mostly
forms of calcite) will glow in fluorescent
colors under a black (UV) light.
• Double refraction- some clear forms of
calcite (Iceland Spar) will make a double
image of words.
Specific gravity
• Specific gravity indicates how many times
more the mineral weighs compared to an
equal amount of water .
• Since water has a density of 1 gram/cm3, and
since all of the units cancel, specific gravity is
the same number as density but without any
units.
• Remember…
Density = Mass / Volume
• Density is how much matter packed in a
space.