Charging a crystal brightens and enhances it’s vibrations, a way of refreshing the crystal energy.
Small crystals can be charged by being placed on a crystal bed or near a crystal cluster. Crystal grids can also be used to charge crystals; placing in the middle of four terminated quartz points inward facing or in the centre of a circle of crystals. Crystals can also be charged by sunshine or moonlight, although some crystals can fade if over-exposed to sun.
I like to charge my crystal collection by leaving them to bathe in the light of the full moon so that the stones feel the power of the moon at it’s strongest, and I believe it is good practice in crystal care to regularly charge crystals to keep the energies fresh or to give the vibrations a boost before a healing session and to empower before programming/dedicating.