Everything in the Universe has a frequency. Crystals have their own unique energies which can work to balance your energy.
Crystal structure repeats throughout the crystal with a near perfect geometric pattern thus it has a more stable frequency. Our bodies are not as stable. Our energies can be altered by stress, negative situations, emotional upset, day-to-day life and more. By using crystals to entrain the chakras to meet the crystals energy this helps to bring the chakras closer to balance.