What are rocks
made of?
Minerals are
not made by
people; they
are …
…naturally occurring
substances.
Name four properties (or
clues) that scientists use
to identify minerals.
Color, luster, streak,
and hardness
Which property means
the way the light bounces
off the mineral?
What words can be
used to describe a
mineral’s luster?
Glassy, dull,
shiny, greasy
Why is color not a good property to
use to identify a mineral?
slate
limestone
Many minerals have
the same color.
What are three testers that
can be used to determine a
mineral’s hardness?
fingernail, penny, nail
What type of rock is formed when
magma cools and hardens?
 There are two types of Igneous rocks
 Intrusive in side the earth
 Extrusive out side the earth
 Granite is an example of an
Intrusive Igneous Rock
 It forms under the Earths surface
from the cooling of magma
 Intrusive igneous are usually rough
to the touch unless they are polished
 Examples: Kitchen Counters
 The Continental Crust of the Earth
is primarily made of Granite
Other examples of Intrusive Igneous Rocks:
Gabbro
Andesite
Diorite
Examples of Extrusive Igneous Rocks
• Basalt is an example of an
Extrusive Igneous Rock
• The Oceanic Crust is
made primarily of Basalt
– Basalt is formed from lava
on the crust of the Earth.
– Because it is formed on the
surface, the crystals are
very fine-grained
Other examples of Extrusive Igneous Rocks
Obsidian
Rhyolite
Scoria
What type of rock is formed when
weathering and erosion cause
sediments to press together in
layers?
Sedimentary Rocks
Sedimentary rocks are formed by the
accumulation of sediments.

Sediments include materials from
sand grain size to boulder size
Clastic Sedimentary Rocks
• Clastic Sedimentary
Rocks are formed from
mechanical weathering
debris
• Mechanical weathering
takes place when rocks
are broken down
without any change in
the chemical nature of
the rocks
Breccia
Sandstone
Conglomerate
Shale
Chemical Sedimentary Rocks
• Chemical Sedimentary
Rocks form when
dissolved materials
precipitate from
solution
Halite
Limestone
Organic Sedimentary Rocks
• Organic Sedimentary
Rocks form from the
dead plants and animals
and their debris.
• Coal and fossiliferous
Fossiliferous Limestone
limestone are examples
of organic sed. Rock
Coal
What type of rock is formed
when change occurs from heat
and pressure in the Earth?
Metamorphic Rocks
 Metamorphic rocks have been modified (changed) by
heat, pressure and chemical process
 usually while buried deep below Earth's surface.
 There are two basic types of metamorphic rocks:
 Non-foliated
 Foliated
Foliated Metamorphic Rocks
• Foliated metamorphic
rocks: have a layered or
banded appearance
known as a foliation
Gneiss
Schist
Slate
Non-Foliated Metamorphic Rock
• Non-foliated
metamorphic rocks
such as marble and
quartzite
• do not have a layered
or banded appearance
Quartzite
Marble
Melted rock below
the Earth’s surface
is called…
Small bits and pieces
of rocks are called…
The breaking down
and wearing away of
rocks is called…
The movement of
sediments from one place
to another is called…