In this collection you will find a host of different crystals that will help you with studying, focus, memory and retaining all the great information you're learning!!! You can use one crystal, many of one type or a combination of crystals. I surround myself with Tiger Eye crystals and Quartz, but there are many others one can use as well. Crystals to help with focus and memory include Quartz, Tiger Eye, Turquoise, Fluorite and Sodalite. See which crystal(s) you are drawn to and start there! Happy studying!