When you first obtain crystals or have been using them for some time they will have absorbed a range of different energies that they will have been exposed to by yourself and others who may have handled them and transferred various energies and emotions into them. Therefore, it's important to 'cleanse' your crystals as soon as you obtain them, and on a regular basis This cleansing process isn't a 'physical' cleaning with soap and water, but intended to cleanse the stone of its stored energies, both good and bad, which can be released again by the stone at any time and once it becomes loaded with energy.
Sunlight – This is probably the simplest method. Place your stones in direct sunlight for about few hours. Make sure it is pure sunlight and not filtered through windows. Be careful not to leave in sunlight for too long to avoid discoloration.
Moonlight – Place your stone in the full moon light to cleanse and charge them with the moon’s gentle energy. This of course can’t be done at any time and should only be done during the single night of the full moon.
Sea Salt – Cover your stones with either sea salt or rock salt granules for several days.
Smudge – Another popular method of cleansing crystals is by 'Smudging'. This involves burning either Smudge Sticks or Incense Sticks and holding the crystals in the smoke to cleanse the stored energies. A feather can be used to fan the smoke across the crystals and this only needs to be done for a short amount of time
Earth – Bury your stones with the point facing upwards and leave for 3 days. Rinse them carefully with pure water.
While you are cleaning your crystals, you need to be fully focused on the task, consciously instructing the stone to give up all stored messages.
Before starting, you may want to clear the room and yourself of extra or unwanted energies by using a cleansing Smudging Stick or Incense.
To program a crystal for specific use or with specific energies, sit quietly away from distractions or strong electrical devices and external energies, then hold the crystal in front of you, clear your mind and focus on the stone. Concentrate on the specific energy that you wish to program the crystal with, and 'transmit' the energies and thoughts from your mind directly to the stone. Be clear and direct when doing this and don't try to confuse or overload the crystal with different thoughts and energies. Do this until you feel happy that the required thoughts and energies have been transmitted to the stone.