The most common method of cleaning crystals in the past has been to put the crystal into a bowl of seawater or a bowl with water that has had salt added to it. This however is becoming a less used method of cleansing crystals as it has been found by past experiences that if left in the salt water for too long it damages the crystal. Thankfully there are other methods about nowadays that cleanse the crystals without actually harming them.
Now as mentioned before some crystals are a bit scared of water and get easily damaged, so a way around this is to cleanse this type of crystal is by means of smudging it with sage or sandalwood, cedar or sweetgrass and fanning the smoke over the crystal or holding the crystal in the smoke making sure that it is immersed.
There are some crystals around that will automatically cleanse other crystals these are invaluable especially to one that has a large collection of crystals. All that one needs to do is place a smaller crystal on or near the permanently cleansed crystal and it will be cleansed by the crystal.
These crystals that cleanse other crystals also never need cleansing themselves, some examples of these types of crystals are:
Amethyst, Clear Quartz, Kyanite, Azeztulite Carnelian and Citrine
I’m sure there are a few others about but these are ones that immediately come to mind.
Cleansing by breath is mostly recommended for cleansing small crystal peaces, and is achieved by holding the crystal in the hand that you write with and taking a deep breath through your nose and focusing you intentions on clearing the stone and exhaling your breath firmly onto the stone from your nose, repeat thing the process until you have covered all sides of the stone either a long slow exhalation or short quick bursts can also be affective it is entirely up to you and what ever way is easiest for you.
There are many methods in cleansing stones which haven’t been covered, one is to actually bath with the crystals, which is not only healthy for the crystals themselves but also very healing for the bather as well. Some gentler methods include immersing the stones in rose petals or lavender petals or sage, thyme or Rosemary leaves or in feathers or charged sand, simply putting the stone on a sacred altar or in a place with healing energies will charge and cleanse a stone over time.