Crystals are natural stones/minerals from the earth. They carry certain metaphysical properties that would naturally come from the earths core. So by removing it, this is why it is important to activate and charge your crystals so the metaphysical properties maintain the same. If not these gems can weaken or loose their benefits by hoarding the energy of the person who has the stone. So cleansing often is highly recommended if they are used consistently. Even if you don't be sure to cleanse before you use them. You then activate or reactivate your crystals every time they are cleansed. This way you can set new intentions. This is no different from taking care of your plants. The same TLC you give to your plants is the same TLC you provide your crystals.
Here are a few ways to charge and activate your gems.
That Moonlight
Crystals love that full moon. Once a month gather those gems, especially the ones you use continuously and place them out in the moonlight. Be sure to bring them back in before sunrise.
Earth
The earth natural soil can help absorb any unwanted energy and refresh them. Place them in a garden or create a simple crystal pit for at least 6-12 hours. A crystal pit is a spot you dig and dedicate to your crystals. Just as you do your garden. Use the natural soil if possible.
Rain
Rain water is the most natural or spring water from a river are also crystals clensers. Be sure to double check if that crystal is water safe. Rain can also charge your gems. Since this is a fertilizer for the earth itself, it is the same for your gems. Rain bathing is cleansing all around. Speak your affirmations and set your intentions if your activating. If you are cleansing you should try not to activate at the same time.
Salt Water
Pink Himalayan Salt or ocean water are great for your water safe stone. Max of 12-24 hours. Be sure to double check if that crystal is water safe. (Florida water is another source)
Incense or Smudging
Burning sacred herbs over your crystals is the fastest way of cleansing them. Some favorites to use are patchouli, Red Drageon Blood Sage and Sage. Palo Santo, Rosemary, Lavender and Peppermint are a few herbs to activate your gems after cleansing.
Running Water
Another simple way is by holding each crystal under a running water for at least one minute each.
Sound
You can utilize Sound to cleanse and activate your gems. Play for a minimum of 10 minutes. Chant or speak affirmations into your crystals to create that deep connection. You can even play to cleanse and then speak your intentions to activate them while playing..