ANSWER: Crystals come in many hundreds of forms, colors, shapes, and sizes. Crystals form naturally in the earth, usually over very long time frames like millions of years. What differentiates a crystal from an ordinary stone or rock is the fact that all the atomic structure in a crystal is uniform and polarized. This property allows crystals to affect the flow of energy, which ordinary stones cannot do. There is extensive scientific reasoning for crystal energy, which I will not go into here as it does not really concern us, but I may post later if anyone is interested!
Upon touching a crystal, body heat and your intention activate the crystal. Once activated, the crystal mingles the Universal Energy Field (UEF) and the Human Energy Field (HEF) including your intent. It is able to direct the flow of energy and balance any discrepancies in your aura.