JOURNAL
Can oil and natural gas be
classified as minerals?
Justify your answer with
information from your notes.
Rocks, Rocks, and
more Rocks!!!!
What is a rock?
• A solid mixture of crystals of one
or more minerals.
What’s so great about
rocks?
• Used to make tools & weapons
– Spears & arrow heads
– Obsidian scalpels used in delicate operations
• Used to make structures (new & old)
• Some contain fossils which help
scientists learn about the past.
A. The Rock Cycle
• The process by which one rock type
changes into another.
• The rock cycle takes millions of
years.
3 processes that change one
rock type to another.
1. Weathering & Erosion
2. Heat & Pressure
3. Melting & Cooling
3 Types of Rocks
1. Igneous Rock-formed by melting
and cooling
2. Sedimentary Rock-formed by
weathering and erosion
3. Metamorphic Rock-formed by heat
and pressure
 Rocks are classified based on how they
were formed
B. Igneous Rock
1. Igneous is Latin for “fire”
2. Igneous rock forms from cooling lava
and magma.
a. Lava is
Earth’s
b. Magma
Earth’s
molten rock that flows on the
surface
is molten rock found below the
surface
3. Igneous rocks make up most of the
rocks on Earth used for building
materials because they are very hard
and last a long time
Examples of Igneous Rocks
Rhyolite
Obsidian
Pumice
Gabrro
Granite
C. Sedimentary Rock
1. Sediments = rock fragments caused by erosion
which is the breakdown of rock by wind, water,
ice or gravity (agents of erosion) and weathering
a. Most are formed underwater
b. Texture is uneven. Why do you think this
happens?
2. Most fossils are found here. Fossils would burn
up in other rock processes but sedimentary rocks
preserve once-living remains
70% of all rocks on Earth
D. Metamorphic Rock
– Meta means “changed”
– Morphos means “shape”
• The structure, texture, or composition
of the rock has changed by pressure,
heat, or the combination of both.