This spell will work for any crystals.
Incense (e.g. Sage, sweetgrass or sandal- or cedarwood)
Start off by putting salt and water in the glass bowl. Fill it up to about two thirds.
If you have porous or metallic crystals (opal, hematite, pyrite etc,) you will want to fill a bowl with just salt and put the crystals in a smaller glass inside the bowl of salt.
You may keep the crystals in the bowl over night, but you should have them in the bowl for at least an hour. You can recite the spell at any time when they are being cleansed.
Before saying the words, light some incense to cleanse the air, or open a window.
Rid these crystals of all energies
good and bad
that may divert focus from each of their purpose
(Hecate, shine your light
upon these crystals
and let them be guided by your divinity
and bless them with your might)
If you want to use a wand, you may draw a triangle over the bowl when you are reciting every line.