http://www.mnh.si.edu/earth/text/2_0_0.html
The Institute of Physical Chemistry "Rocasolano" (IQFR) is located at the seat of the former National Institute of Physics and Chemistry
http://www.xtal.iqfr.csic.es/Cristalografia/index-en.html
Victoria and Albert Museum Video on Crystallography - The study of the internal structure of crystals
http://www.youtube.com/watch?v=RkRYe1J7cHE
Simpler reading and Experimental Investigation
http://www.sciencebob.com/experiments/rockcandy.php
http://www.exploratorium.edu/cooking/candy/recipe-rockcandy.html
http://www.minsocam.org/MSA/collectors_corner/id/mineral_id_keyi1.htm
Crash Course: Solids
http://www.youtube.com/watch?v=bzr-byiSXlA
http://www.youtube.com/watch?v=tbu-egineUo