Sawing a Local Bedrock Specimen

In this activity students bring in samples of local rocks for the teacher to cut in half with a diamond saw. Students then analyze and report on the grain relationships within the rock. As a follow-up activity students can exchange rocks, write an analysis of the sawn sample, and compare notes. In cases where disagreements cannot be resolved, the teacher should offer a third analysis of the sample. Also students can take the rocks home and tell their parents what they learned about the particular sample. Or they can set up before-and-after displays showing cut and uncut samples. Enlarged poster-size diagrams of the more interesting samples can be created. The specific details of texture and composition can be labeled with a string or wire running to the appropriate spot on the specimen. Educational levels: Middle school, High school