1. What are the two environments that Igneous rocks can form in?
2. Which environment is below the Earth’s surface?
3. What type of texture do intrusive igneous rocks have?
4. Where are pumice and obsidian formed?
5. What is the grain size, in millimeters, of rhyolite?
6. What is the color, density, and composition of granite?
7. Which of the following rocks has the highest content of iron: granite, obsidian, basalt, or pumice?
8. List all the minerals that can be found in granite.
9. The mineral pyroxene can only be found in which of the following rocks: rhyolite, pumice, basalt?
10. Igneous rocks with a felsic compostion contain which element?
11. Igneous rocks with a mafic compostion contain which element?
12. Which mineral is found in rhyolite bu not scoria?
13. What does a vesicular texture mean?
 
 

ANSWERS

1. Intrusive (plutonic) and extrusive (volcanic)
2. Intrusive
3. coarse or very coarse
4. Near volcanoes (on surface)
5. Less than 1 mm
6. light, low, felsic
7. basalt
8. potassium feldspar, quartz, plagioclase feldspar, biotite, amphibole
9. basalt
10. Al
11. Fe & Mg
12. quartz or potassium feldspar
13. holes or gas pockets