Igneous rocks are formed by the cooling and hardening of lava or magma. There are two main types - intrusive rocks, which solidify underground, and extrusive rocks, which form above ground from lava. The key differences between igneous, sedimentary, and metamorphic rocks are that igneous rocks form from the cooling of magma or lava, sedimentary rocks form from the compaction of sediments, and metamorphic rocks form from the alteration of pre-existing rocks by heat, pressure, and chemical processes within the Earth.

1. IGNEOUS ROCKS
By Sophia Carter and Danny Lee

2. H OW I G N E O U S RO C K S A R E
FORMED
 Igneous rocks are rocks formed by the cooling, hardening, and the
freezing of lava or magma
 Igneous rocks may or may
not crystallize while cooling
 Most of the 700 igneous rocks
are formed under the Earth’s crust

3. THE ROCK TYPES AND
THEIR DIFFERENCES
 Igneous
 Sedimentary
 Metamorphic
 The difference between igneous and metamorphic is that the metamorphic rocks are
formed under pressure and igneous rocks are just cooled off lava/magma.
 The difference between igneous and sedimentary rocks are that sedimentary rocks
are made of different rocks, animal parts, and plants mushed together to make one
rock.

4. I N T RU S I V E A N D E X T RU S I V E
RO C K S
Intrusive rocks: Extrusive rocks:
 Solidified inside the  Solidified above the
Earth’s surface Earth’s surface.
 As the active volcano  First a volcano erupts or
turns into a extinct magma/lava oozes out
volcano, the lava /magma the volcano. Then the
inside hardens and magma/lava cools or
becomes a Intrusive hardens to form a
Igneous rock extrusive igneous rock

5. T Y P E S O F I N T RU S I V E A N D
E X T R U S I V E I G N E O U S RO C K S
Extrusive rocks: Intrusive rocks:
 Basalt  Diorite
 Obsidian  Gabbro
 Pumice  Pegmatite
 Rhyolite  Granite
 Scoria

6. THE ROCK CYCLE
This is the rock cycle:

7. WE HOPE YOU WERE
LISTENING! THAT’S BECAUSE
THERE IS GOING TO BE A
QUIZ!

8. QUIZ!
 What rock is this rock?
 Is a Gabbro an intrusive or an extrusive rock?
 What’s the difference between an intrusive and a extrusive rock?
 Who are the authors of this PowerPoint?

9. A JOKE
Q=What music does rocks like best?
A=rock & roll!

10. WORDS YOU MAY NOT
KNOW/INDEX
 Crystallize- A form of a rock slowly or quickly turned into a
crystal/rock
 lava/magma-a liquid that is formed inside a volcano, and when
cooled off it’s turned into a igneous rock
 Sophia-wisdom
 Danny-Clear water of the East Sea

11. ANY QUESTIONS?
Ask a question
Or we’ll tickle this cute
kitty!

12. APPLAUSE FOR US!
(Please)