New stones, provided they are not water-soluble or too fragile (be sure to look it up!), benefit from washing in warm, soapy water to remove dust and grime. More importantly, your stones should be energetically cleansed before and after each use. This is because a crystal functions by absorbing energy from its surroundings into its internal structure, where imbalances are corrected. If it is not cleansed, the crystal will become overloaded, which reduces its effectiveness and may cause it to transfer imbalances into the aura.
Cleansing Methods.
Running water and sunlight: hold the stone under running water and visualise imbalances flowing away. Place in sunlight to dry. Not suitable for water-soluble crystals, fragile crystals or crystals that fade in sunlight.
Sound: Strike or ring a singing bowl, bell, cymbal or tuning fork near the crystal.
Incense smoke: Incense has always been used to cleanse and consecrate. Burn some incense and pass the stone several times through the smoke.
Salt: place the crystal in a bowl and cover with dry sea salt. Leave to stand overnight. Avoid placing crystals in salt water to protect their surfaces.
Breath: exhale sharply over the crystal and imagine imbalances being blown away. Repeat several times.
Crystal clusters: place the stone on any larger crystal cluster to restore natural levels of energy.
Essence Sprays: spray the stone with a cleansing flower and gem essence.
From: The Essential Crystal Handbook by Simon and Sue Lilly. Available in The Works for around £2 (usual price £8.99)!