Crystal picks up the energy of things around it, including the environment, just as anything else does. Crystals also need charging to have its full energy. I am going to tell you how to deal with this.
This energy picked up may be positive, neutral, or negative energy. Whichever type it is, it affects the way the crystal energy works. Thus, it is best to clear crystal energy before using the crystal. Charging a crystal before use is also a good idea. Charging gives the crystal or stone its full energy to work with. There are many ways of clearing a crystal. Also, there are many ways of charging a crystal. I am going to concentrate on methods that can do both at the same time.
No matter which method you use, before you use it, you need to set your intention. Setting your intent can be as simple as intending and stating, “I intend this _(sunlight, moonlight, etc.)_ to clear and charge this(these) crystal(s).” You can also do elaborate ceremonies, but the sincere intention and statement work as well, in my experience.
Sunlight: Setting a crystal in the sun for 12 to 24 hours or more can clear any unwanted energy. Plus, it can give it an energetic charge. You can sun your crystals on the back deck, in the garden, on a window sill, or wherever the crystal will be safe. Be careful, though, that you avoid this method with stones that can fade in sunlight. Some of these are Amethyst, Rose Quartz, Prasiolite, and most light-colored crystals. For those crystals, another method is a better choice. If you are not sure, use a different method.
Moonlight: Setting a crystal in the moonlight for 2 or 3 nights clears and charges the crystal. Also, it will not fade light crystals. Most people prefer the 2 or 3 nights around the full moon, but I have used a wide variety of moon phases successfully. Just place your stone where it can catch full moonlight and leave it during the moonlight hours. During the day, remove it to avoid sunlight. The put it in the moonlight the next night.
Burial: Burying a stone is to return it to the Earth to recharge and be cleared. You can bury it in a patch of garden or anywhere in the yard. Just be sure to mark where you have put it. Additionally, you can put it in a large pot of dirt. This has the advantage that it can be done in an apartment or other small space. The dirt in a pot will need to be changed when it feels “full,” but that is simple to do.
Other Crystals and Clusters: There are several stones that can clear and charge other crystals. Clusters of Amethyst, Quartz, and Citrine are particularly useful to charge crystals. “Logs,” “plates,” or multiple pieces of Selenite, Carnelian, and Kyanite are also excellent choices. Put the crystals to be charged on top of or touching the side of the Amethyst, Selenite, or other crystal you have chosen. Leave it there from 4 to 24 hours. Tip: Be sure first to use another method to clear and charge the crystals you use to clear other crystals.
Reiki: Reiki or another healing energy mode is an excellent way to clear and charge crystals. One way is to energize it the way you would a Reiki bear. Another is to literally initiate the crystal.
Sound: (Links are Amazon ads, but it doesn’t matter where you get these items.) Some sounds are both clearing and energizing. In particular, OM (or AUM), the ringing of a gong , the sound of bells, singing bowls or ringing tingshas are good for this. Repeat the sound at least five times. If moved to do so, repeat it additional times.
There are other methods that either charge or clear crystals. I find these methods that do both the easiest and equally effective. I hope you find them useful.