Many who use crystals do so to effect change both internally and externally.
They may desire to internally calm their minds or spirits, heal their bodies, encourage and/or maintain wellness. Externally they may want to draw prosperity into their lives, enhance personal or professional relationships, protect their homes, possessions, pets, and loved ones.
Whatever the goal of your practice, regular cleansing/clearing of crystals is necessary to restore them to their natural state before and after use. Some of the most common methods used to cleanse or clear crystals are moonlight, sunlight, smoke, water, sound, and visualization.
When cleansing stones under moonlight, for the most effectiveness, you would want a waning moon, which can be thought of as decreasing the stagnant, negative energy in the stone just as the size of the moon is decreasing. Overnight should be sufficient, but follow your own intuition for how long to leave them to clear under the moon light.
Using sunlight for cleansing stones is essentially the same process. Place the crystals in a safe place and allow the heat of the sun to burn away what has built up in your stone. A day should do it, but again, trust your own gut.
Cleansing with smoke is often done by lighting a sage (or any other Cleansing herb/material) smudge stick and passing the stone back and through the smoke until it's energy feels clear.
Cleansing with water should only be done with stones that aren't sensitive to moisture. You wouldn't want to clear selenite with water, for example as this stone can eventually over time weaken in water. Living water, such as creeks, rivers, a lake, or the ocean is generally preferable when cleansing stones, but in a pinch passing them through running tap water can be beneficial as well. Placing the stone in a mesh bag or strainer and placing in the current or holding in your hand are effective methods for utilizing the cleansing power of living water.
Some use sound in clearing crystals. Chanting, singing bowls, tuning forks, and bells can all be used to envelope the stone in sound, thereby raising the stones vibration to that of the sound, essentially shaking off the negative energy attached to it.
Visualization is especially effective for this purpose. You want to ground and center your energy, hold your stone, and visualize impurities draining from it and the stones energy brightening.
Selenite is also a natural cleanser. Placing your crystals on a selenite slab over night is a great way to cleanse them. Selenite itself does not need to be cleansed.
Taking the time to program or charge your crystal with your purpose or intention will allow you to connect energetically to your stone and focus its energy. Visualization is a powerful way to charge your crystals with your purpose. Hold your stone and envision the stones energy merging with your own, absorbing your intention.
When charging your stone with the power of the moon, expect to work with a subtle feminine energy . Place your stone where it will receive moonlight during a waxing/full moon to charge it. Overnight is usually sufficient. The same is done when charging under the sun. Just place your crystals in a spot where they won't be disturbed to absorb the sun's fiery masculine energy throughout the day.
Whichever method or combination of methods you choose for clearing and charging your crystals, this act of care will increase your bond with your stones and reinforce the focus of your practice.