Since crystals can store and transmit energy, it is important you cleanse them of unwanted or negative energies on a regular basis.
Every time your crystals come in to contact with somebody other than yourself, an imprint of that person’s energy is left behind, making it even more important to cleanse your crystals if they are handled by anybody other than yourself.
This article at the School of Energy Medicine tells us how to cleanse our healing crystals.
The common methods of cleansing include:
Water. Leaving your crystals in natural or purified water overnight will cleanse your crystals of any negative energy. This method works best on the night of a full moon.
Sea salt. Completely cover your crystal in a container of sea salt and leave it overnight.
Sea salt water. Leave the stone is a container or glass of sea salt water overnight, in the morning rise them in clear water to remove any salt.
Burying. Burying your stone in soil for at least one week is one of the most intense cleansing methods, appropriate for stones which have been overworked.
Remember, not all methods of cleansing are appropriate for every crystal or stone. For more cleansing methods, and to find out which is best suited to your crystals, visit the article in full.