It is important to cleanse a crystal when you receive it. Crystals naturally absorb energy and cleansing it removes energy it has picked up along the way before reaching you. It is important to also cleanse your crystals after you have been working energetically with them, such as in healing work or meditation, as they absorb the persons energy you have been healing and it can be passed on if you don’t clean it out of the crystals.
When to cleanse
You will know when a crystal you have been working with needs to be cleansed. Quartz crystals may become cloudier, where they were bright and clear before, other crystals will lose their luster. Some crystals physically feel denser or heavier, like they are carrying a burden or extra load.
The crystals you wear or have around the house will need cleansing regularly, depending on how much you wear them or how much action is going on in the house.
Also, you will need to cleanse your quartz crystal when you want to reprogram it to do something else.
Methods for cleansing crystals
To cleanse your crystal you use your energy to work directly with the crystals’. This is done through your intention – a focused mind. While holding your crystal in your hands, visualize it immersed in white light, clearing it of any unwanted energies and re-energizing it. Hold it for several minutes or as long as you feel inclined. Ask “that all the energies within the crystal are transformed into divine light and love, and that it is clear and activated to its full potential”.
Most crystals love running water. Hold your crystal under the tap and allow cold water to flow over it. As you do so, visualize all negative energies dissolving and washing away, transforming into positive healing energy
Visualize a flow of clear, pure mountain water going through the crystal, washing away all impurities and seeing them transformed into positive healing energy.
Rinse or bathe your crystals in rain-water, water from a spring, a stream, the beach, a river or sacred source, even in a waterfall (make sure you hold on to them or they can get swept away). Dry them naturally in gentle sunlight.
Morning sunlight gently cleanses your crystals and moonlight is a softer way to let light filter through your crystals and cleanse them. The best time for this is a full moon.
Using the smoke of sacred herbs such as sage, cedar, and lavender to smudge and cleanse the energetic matrix of crystals. Smudging with white sage removes negative energy from crystals and rooms in your house. (Smudging is to light the herbs and burn them, when the flame dies the embers burn creating smoke. You then pass your crystal through the smoke while asking it to be cleansed and purified.)
Place your crystals on a bed of rock salt for 24- 48 hours to purify the crystal’s energetic matrix.
Bury them in the earth, soil or clay for 2 –7 days as this provides a slow and gentle form of cleansing. The longer you leave it the deeper the cleansing. (Make sure you the spot where you buried your crystal as they wriggle away and can get lost in the earth)
Cold running water – from the tap is fine for most crystals. Never use warm or hot water. Water is not recommended for soaking calcite, opals (doublets and triplets), pearls, celestite, unpolished malachite or turquoise as due to their composition they can dissolve or be permanently damaged.
Recharging your crystals
We recharge crystals to give them renewed energy. There are many ways to do this:
Placing your crystals in sunlight for an hour or so, will charge most crystals. After a sunbath on your windowsill, your crystals will be noticeably brighter. You can also place your crystals on the earth for an additional charge while recharging them under the Sun, Moon or Stars.
Placing your crystals out under Moonlight is a gentle and penetrating method for recharging your crystals. The full moons’ light is the brightest in its cycle, thus giving a greater charge to your crystals.
Placing them out in any dynamic weather conditions such as a thunderstorm provides an awesome electromagnetic charge to your crystals.
Placing your crystals on an amethyst cluster is great for recharging jewellery and smaller crystals. You can also place your crystals on a clear quartz cluster that you have programmed to recharge any crystals you put on it.
Your crystals like to be out in the open, where they can work to their full potential. Keep them on material or in a bag that is made from silk, satin, velvet or cotton – not man made fibres. Crystals need to be treated carefully as they are fragile and can chip and split. If you carry them with you keep them in a bag so they are protected.
Storing your mineral specimens
Select a location that’s dry and clean. Exposure to salt air (common in coastal areas), dust, or moisture can damage or destroy some specimens.
If possible, use boxes made of plastic or acid-free materials to prevent chemical reactions between the specimen and it’s container.
Keep small, fragile, or soft samples in individual or divided containers that are lined with tissue. An economical way to store small, fragile samples is in an egg carton.
Try to keep each specimen separate so harder minerals don’t damage softer minerals
Don’t use cotton balls or pads to line your boxes. The fibers can stick to your specimens.
Each specimen is unique and can never truly be replaced. Each is collected at a single point in time, from a specific geographic location, and has a unique genetic or geologic history.
borrowed from: http://www.thatcrystalsite.com/articles/care-of-crystals.php#Top