Crystals each have their own energy field. Just as with people, the energy field of a crystal can pick up other energies. As a crystal healer I work with the stones and they accumulate positive healing vibrations; however the crystal is also susceptible to negative vibrations, for example from people, or electromagnetic radiation from televisions and computers.
When I utilise crystals for healing I am using them to bring about changes in my client's energy field. If the crystal is holding onto negative energies then the result may be far from therapeutic! The same will go for you if you use crystals at home. You should always cleanse your crystals when you first acquire them and then cleanse them after use.
Most crystals are mined. Sadly the people doing the mining may not be working in conditions conducive to a loving `birth'. Crystals may be handled roughly and most have a long journey to make. They may then have been sitting on a shop shelf being handled by dozens of people over a long period of time. Although many reputable suppliers do know about cleansing and will cleanse all of their stock on a regular basis, you cannot know who has since touched them and the vibrations they carry, therefore it is advisable always to cleanse your crystals after purchase.
When you have been using crystals you may have loosened some negative energy from your aura or that of the person youve used them on. If you don't then cleanse crystals you may transfer this negativity. Over time jewellery may also accumulate negativity, especially if you use it for protection.
Some methods of cleansing are more thorough than others. It is appropriate to use deeper cleansing when you have just bought a crystal and also if you notice a crystal seems dull or has a `heavy' or `sticky' feel about it.
Frankincense has a long history of use as a spiritual cleanser- traditionally it is used in churches to lift the vibration and clear negativity. Burning frankincense grains on a charcoal disc is a method of deep cleansing a large number of crystals (and the room into the bargain). Always take precautions with lighted charcoal. Ensure you place the burner on a heatproof surface out of reach of children and animals.
Some people prefer to use smudge sticks, a traditional Native American cleansing method. The ingredients vary; however traditional herbs such as sage and sweetgrass should make up a high proportion of the stick. Again take care when waving a lit smudge stick, bits can fall off and cause scorching. Have a saucer or fireproof dish ready to put the stick out, as once lit it may keep on burning unless thoroughly stubbed out. Never leave a burning smudge stick unattended.
Salt is a traditional cleansing agent. It has absorbent properties both physically and on an energy level. Place crystals in a bowl of sea salt. Use your intuition or dowsing to guide you to the length of time to leave them. Be aware though that salt can damage some crystals. Do not use this method on opals, as salt will absorb the water content, which makes them iridescent.
Stones come from the ground and have grown within the natural energies of the Earth. Burying them in earth is a useful deep cleansing solution to be used where a stone has been traumatized, feels very unhealthy and needs to rest. Bury the stone in your garden or in a pot of earth if you haven't got access to a garden. Label the spot well if you want to be able to retrieve the stone and leave it. It will probably need weeks, or even months to recuperate- you can always check on its progress and rebury it if necessary.
Most of the time lighter methods will suffice. Hold the crystal under running water and visualize white light running through it and washing all negativity away. Tap water will do- but a clean stream or waterfall is lovely. Bear in mind some crystals are water soluble- selenite would be ruined by this method for example.
Spraying a fine mist of a gem essence created with cleansing in mind will cleanse crystals very quickly. This is particularly useful method I use for cleansing between clients, where I need to use the same crystals again and haven't time for other methods. You can create your own gem essences and many suitable essences are available commercially.
Sometimes other methods of cleansing are not available. Fortunately you can use the power of intention to cleanse crystals. Hold the crystal in your palms and visualise it being cleansed by a stream of white light.
Finally, dont be tempted to skip the cleansing of your crystals. It is a basic and important first step in working with them.
If you'd like to experiment more with crystals I think this Sue & Simon Lilly book is a great introduction.