1. Igneous Rocks

2. Igneous Rocks
Igneous rocks form when molten rock cools and hardens.

3. Magma or Lava? Magma: molten rock under ground
Lava: Molten rock above ground

4. 2 Types of Igneous Rocks Extrusive- cool and harden at the surface
- they cool fast so they don’t have time to form big mineral crystals
Intrusive- cool and harden under the earth’s surface
-they cool slow so they form bigger mineral crystals

5. Igneous rock formation

6. Igneous rock formation

7. Basalt Color- black Made of- lava How formed-extrusive (cooling lava)
Other-
aa- rough lava
pahoehoe- smooth lava

8. Obsidian Color- black (clear) Made of- volcanic glass
How formed-extrusive, cools VERY fast
Other – arrowheads, sharp

9. Red Pumice Color- red Made of- frothy volcanic lava
How formed- extrusive
Other- bubbles (vesicles), very light weight

10. Black Pumice Color- black Made of- frothy volcanic lava
How formed- extrusive
Other- bubbles (vesicles), very light weight

11. White Pumice Color- grey white Made of- frothy volcanic lava
How formed- extrusive
Other- bubbles (vesicles), floats

12. Granite Color- red, white, black, grey, etc…
Made of- quartz, many other minerals
How formed- intrusive, far under ground so crystals can slowly grow bigger
Other- large crystals

13. Rhyolite Color- grey, pinkish Made of – quartz and other minerals
How formed- intrusive
Other- small crystals

14. Igneous Rocks Info Sheets
7 Igneous Rocks Picture on page 83 Name, picture, extrusive or intrusive?, other characteristics 1. Basalt extrusive aa- rough pahoehoe-smooth 2. - labelled 3. - colored 4. - intrusive: cool underground slow 5. : big crystals 6. - extrusive: cool aboveground fast : small or no crystals 7.