http://uts.cc.utexas.edu/~rmr/
Rob's Granite Page. Go to "Granite for beginners."

Find the photo of granite. You can click on some of the minerals to find out what they are. What is the pink mineral? Why is it generally the principal influence on the color of granite? What is the white mineral? How does this mineral differ chemically from the pink mineral? What is the black mineral? Note: you can't tell what the mineral is from looking at the picture, other than it is a ferromagnesian mineral. What physical property that you learned about in the mineral chapter would allow you to determine in a real rock that the mineral is biotite. Can you find the quartz? It looks slightly greenish in the picture and if you click on it, it is described as "somewhat yellow." This is not the usual color of quartz, usually it is a, somewhat transparent, light gray.

Look at table giving the average composition of granite. What is the weight percentage of SiO2? Why does this high percentage of silica mean that there will be quartz in granite?

http://seis.natsci.csulb.edu/basicgeo/IGNEOUS_TOUR.html Igneous Rocks Tour. Go through the pages and take the quiz at the end. Answers are given so that you may check on how your did.