All Crystals and Gemstones require energetic cleansing periodically to clear away stagnant or negative energies that they have absorbed.
The best way to do this is to use a smoke clearing technique with sage, sweet grass or palo santo sticks. There are many youtube or written articles on how to do this, but all involve directing the smoke towards the crystals with the intention of clearing away any energies that do not serve you.
Some stones do fine in water (such as many different types of quartz), however many do NOT do well in water (such as Selenite), therefore I recommend clearing with smoke instead.
Crystals and Gemstones LOVE charging under the light of a full moon, this is a great way to bump up their vibration. Just make sure they aren't placed in an area where they might get wet if you are leaving them out overnight. Also, remember to bring them back inside the next day as some crystals lose their colouring if left under direct sunlight for too long (such as with Amethyst and Rose Quartz).
When you receive your crystals, I recommend taking a moment to place them next to your heart and connecting your energy with theirs. This is not a must-do step, but it strengthens the energetic connection between you, and increases the healing energy of the stones.
Before you receive your stones, I set an intention with them for the specific healing properties for each bag. You can also do this at home, and expand it to include your particular circumstances for more individualized healing.
Enjoy!!
