1. Rock Identification Lab

2. Question 1 Define Igneous Rock
1. Igneous rock forms when hot, liquid rock, or magma, cools and solidifies. P.36

3. Question 2 How do igneous rock forms
Igneous rocks form when magma of different compositions cool at varying rates

4. Question 3 What are the 2 basic classification of igneous rock.
Intrusive igneous rock- Rock formed from the cooling and solidification of magma beneath the Earth’s surface
Extrusive igneous rock-Rock that forms as a result of volcanic activity at or near the Earth’s surface

5. Question 4 Describe how the chemical composition of the rock affects the color of the igneous rock
- Light rocks/ Felsic- less dense contain more silicon, aluminum, potassium, and calcium
-Dark rocks/ mafic- more dense contain calcium, iron, magnesium and poor in silicon

6. Question 5 How can you tell how long it took an igneous rock to cool,
An igneous rock that has cooled at a very fast rate has little or no crystals, and is often times smooth or is fine grained.
An igneous rock that has cooled at a slow rate has large crystals or is coarse grained.

7. Question six See website

8. Pumice Fun fact- this rock is also called “Lava froth” Color- Light
Texture-porous and rough, formed at earths surface so it has very few crystals
This rock is not porphyritic, it typically contains only one type of mineral

9. Rhyolite Fun fact- Rhyolite has a composition of over 60% silicon
Light in color
Fine grained, aphanitic texture, crystals are very small and can hardly be seen by the unaided eye
It is extrusive
Not porhphyritic

10. Obsidian Fun fact: also known as nature’s glass Dark in color
Glassy texture
Extrusive
Non porphyritic l

11. Quartz composite igneous rock
Fun fact- minerals can make up rocks, but rocks can not be minerals
Color- light
Texture- coarse grained
This rock is an intrusive igneous rock

12. Andesite
Fun facts-Andesite is the most common volcanic rock after basalt.
Color-Lighter gray, contains about 50% silicon
Texture-fine grained
Extrusive
This is a porphyritic rock because it contains the minerals quartz, horns blend, and mica

13. Pegmatite
Fun fact- this rock often fools people into thinking it is sedimentary because of its very coarse texture and large crystal deposits
Color- displays a wide variety of color
Very coarsed grained texture
Intrusive
Porphyritic- typically containing a mixture
Of quartz, feldspar, and mica

14. Basalt
One of the most common mafic igneous rocks *It’s on pg. 37 in your textbook
Color darker/ mafic rock
Fine grained texture
Extrusive
It is pyrophyritic

15. Scoria
Fun fact: it is bubbly, it is often used for a base to make roads
Color- dark gray to black
Vesicular texture/ coarse grained
Extrusive rock
Can be porphyritic

16. Syenite Fun fact- looks like granite
Multicolor- typically a white, black, gray blend
Semi-coarse grained
Intrusive rock
Has a blend of different minerals, which makes it porphyritic