Why do crystals need cleansing? Crystals work to absorb energy, both negative and positive from all that they come in contact with. For this reason, they need to be cleansed, the more you take care of and respect your crystals the more useful they will be to you. Your crystals become in tune with your energy field and serve you with their ultimate power but they can’t do this when they are full of mixed energies. It is so important to keep your focus and intention clear and positive while doing your cleansing ritual.