1. Rocks
“A rocks a rock! A mineral is a rock too! There’s no difference!”
Rock – a mixture of minerals or organic matter
Three types of rock:
Igneous
Metamorphic
sedimentary

2. Igneous Rocks
Igneous rocks were once completely melted rock (in a liquid form) that have cooled and solidified
Formed from magma or lava
Magma? Lava? “what’s the big deal?”

3. Igneous Rocks: Grain Size
Igneous rocks with large grains are called intrusive rocks
Slow cooling = large grains (underground)
Igneous rocks with small grains are called extrusive rocks
Fast cooling = small grains (above ground)

4. Igneous Rocks: Composition
Light colored rocks are made of light minerals
examples:
Dark colored rocks are made of dark minerals
Minerals are evenly spread in Igneous rocks

5. Igneous Rocks: cooling rate
Intrusive rocks
Form slowly beneath the surface (=______ grains)
Extrusive rocks cooling rates
fast: Can flow out of volcano as lava
faster: Can be shot out of volcano and into air (air bubbles can form in the rock)
fastest: can prevent crystals from forming