1. Igneous Rocks

2. Igneous rock definition
Rocks formed by the cooling and solidifying of molten materials. Igneous rocks can form beneath the Earth’s surface from magma, these are intrusive igneous rocks
Or on the earths surface from lava, these are extrusive igneous rocks

4. Igneous Rock characteristics
Texture: Very Course, Course, Fine, Glassy, Vesicular and non-vesicular
Color: Light or Dark
Density: High or Low
Composition: Felsic Al, Si or Mafic Fe, Mg
If a Rock is Dark in color it will also have a Mafic composition and a High density.
If a rock is Light in color it will also have a felsic compostion and a Low density

5. Very Course to Course Texture
Crystal size
1mm to 10mm
Very Course
Crystal size
10mm or larger

6. Fine Texture
Fine
Crystal size
Less then 1 mm

7. Meaning no visible crystals
Glassy Texture
Crystal size
Non-crystalline
Meaning no visible crystals

8. Vesicular Texture
Visible gas pockets

9. Mafic Intrusive rock Gabbro
Large crystals
Dark in color

10. Mafic extrusive rock Basalt
small crystals
Dark in color

11. Felsic Intrusive rock Granite
Large crystals
Light in color

12. Felsic extrusive rock Rhyolite
Small crystals
Light in color