Metamorphic Rocks Laboratory

  • Write a short paragraph describing each of the two rocks (thus two paragraphs).
  • Photograph each rock with a sense of scale (a pen, a coin, a ruler). The photographs must be in focus. Use the “macro” setting on your camera; usually it’s indicated by a little “tulip” icon like this:
  • Post your pictures in the Rock Identification Working Area discussion board (one thread per assigned group of three students).
  • With your assigned group (again; see Announcements), collectively identify your rocks and verify each other’s identifications. You can seek validation of your identifications from the instructor.
  • Once the identifications are solid, collaborate to answer the following five questions for each rock sample in the group:
  1. What type of rock is this? (igneous, metamorphic, or sedimentary)
  2. What are the dominant minerals in the rock? (e.g., quartz, biotite, calcite, etc
  3. What is the name of the rock? (e.g., basalt, granite, sandstone, etc.)
  4. Where is this rock from? (Where did you obtain the rock?)
  5. What processes were responsible for creating this rock? (Interpret the history behind this rock sample.)

If igneous, describe the character of the melt that generated the rock (mafic or felsic) and its cooling history (aphanitic vs. phaneritic: extrusive or intrusive?).