Lab Activity #9: Igneous Rock Lab
Objective: Identify igneous rocks based upon their texture and composition.
Vocabulary: In order to complete the lab, you will need to first identify these
vocabulary terms. Use pages 70-74 of your text to help
1. Texture:
a. Coarse-grained:
b. Fine-grained:
c. Glassy:
2. Composition:
a. Granitic:
b. Andesitic:
c. Basaltic:
3. Intrusive:
4. Extrusive:
Using a sample tray of igneous rocks and the classification table provided, fill out the
table below.
Table 1: Igneous Rocks
Sample
Number
Texture
(coarse- or finegrained, glassy)
Composition
(granitic,
andesitic,
basaltic)
1.
4.
5.
9.
10.
11.
12.
14.
15.
1
Intrusive or
Extrusive
Rock Name
Analysis Questions
1. Based upon your data, what is the relationship between texture and where the
igneous rock forms?
2. What is therefore responsible for the different textures in igneous rocks?
3. What is the relationship between composition and the color of the igneous rock?
4. By what two major categories would you use to divide all igneous rocks?
5. How are all igneous rocks formed?
2