PROBLEM: Are all volcanic rocks the same?

PREDICTION: 

PROCEDURE: Look at the rock from Mt. Lassen in California. Describe it using some of the following words: black, gray, light, heavy, has visible minerals, glassy, holey, shiny. You may use your own words. After you look at Mt. Lassen, look at the other 3 rocks and describe the rocks. Use some of the same words as above.

DESCRIPTION

Mt. Lassen, CA

Mt. Shasta, CA

Clearlake, CA

Mono Craters, CA

Mt. Lassen is a composite volcano. It is made of lava and ash. Mt. Lassen erupted in the 1915 but it is now sleeping (dormant). Using clay, make a model of Mt. Lassen. Save the model, it will be used in a later lab.

CONCLUSION: How are volcanic rocks different?