IGNEOUS ROCKS

1
IGNEOUS ROCKS
2
IGNEOUS ROCKS

• 1. Igneous Rock - Rock that forms from magma or
  lava most are made of mineral crystals

3
IGNEOUS ROCKS

• 2. Extrusive Rock (origin) Igneous rock formed
  from lava that erupted onto Earths surface
  (basalt from oceanic crust)

GLOWING BASALT
OBSIDIAN
BASALT
4
IGNEOUS ROCKS

• 3. Intrusive Rock (origin) Igneous rock that
  formed when magma hardened beneath the Earths
  surface (granite from continental crust)

GRANITE
5
IGNEOUS ROCKS

• 4. Texture Depends on the size and shape of the
  mineral crystals intrusive rock has larger
  crystals

6
IGNEOUS ROCKS

• 5. Fine-Grained (texture) From rapid cooling of
  lava (extrusive) has small crystals

RHYOLITE
7
IGNEOUS ROCKS

• 6. Coarse-Grained (texture) From slow cooling
  of magma (intrusive) has large crystals

GRANITE
8
IGNEOUS ROCKS

• 7. Porphyritic (texture) Intrusive rocks they
  have large crystals scattered on a background of
  much smaller crystals forms when intrusive rock
  cools in 2 stages

9
IGNEOUS ROCKS

• 8. Mineral Composition (silica content in magma)
  Rocks with a low silica content form dark
  colored rocks (basalt) Rocks with a high silica
  content form light colored rocks (granite)

HIGH SILICA CONTENT
LOW SILICA CONTENT
10
IGNEOUS ROCKS

• 9. Other Characteristics of Igneous Rocks Hard,
  dense, durable, used for tools and building
  materials