Name _____________________________________________________ Period ________ Date____________
Igneous Rock Lab
(Advanced)
Vocabulary: On the back of this paper, define each of the following terms as it relates to igneous rocks.
igneous, intrusive, extrusive, felsic, mafic, lava, magma, composition, texture
Data: Complete the chart as you observe each rock sample. Do not use the reference chart to identify the names of the
rocks until you have completed collecting your data
Number
Color
(light/medium/dark)
Composition
Texture
(felsic/mafic/
intermediate)
(fine/coarse/glassy/
porphyritic/vesicular)
Intrusive/Extrusive
(or both)
Rock Name
1
2
3
4
5
6
7
8
9
Analysis Questions: Answer each question and the conclusion using complete sentences. Use your book to help you if
you need additional information. Remember; give specific examples from the lab in each answer.
1. How is the size of the mineral grains affected by the rate at which molten rock material cools?
2. How can you determine if an igneous rock has had an intrusive or extrusive origin? How can it sometimes be both?
3. How does the mineral composition of a light-colored igneous rock differ from that of a dark-colored igneous rock?
(What specific elements are found in each?)
4. How does the density of a light-colored igneous rock differ from that of a dark-colored igneous rock? Why?
5. Conclusion: Explain how to go about classifying igneous rocks. Explain in detail what you did in this lab, and give
examples!
Vocabulary definitions:
Igneous
Intrusive
Extrusive
Felsic
Mafic
Lava
Magma
Composition
Texture