The majority of the crystals you work with, wear, and hoard I mean display around your home and workspace will pick up energy. You don’t really want all that energy attached to them, especially protective stones as they can often protect you by absorbing negativity and ill intent. The energy they collect isn’t necessarily always bad, but it may not be aligned with what you’d like to work with your crystal for. Allowing people to touch your crystals, using them for healing and wearing them can all cause your gemstones to pick up extra energies.
