Crystals have an energetic vibration based on their molecular blueprint.
When a crystal is introduced to your own energy field, it is believed that the crystal will cause your energy to go through entrainment.
What is entrainment?
Entrainment is the process in which your energy synchronizes to the energy of the crystal.
Your energy will begin to mimic the energy of the crystal and bring you back into balance.
Certain crystals give off different energy vibrations and what crystal you need will change depending on what your body needs to bring itself back into balance.
View this video below to see an example of entrainment.