I asked a friend who was going shopping to pick up some salt for me for a spell. He got it into his head it had to be the best salt you he could find. He returned with a giant smile, and said he had a special present for me. It was a bag of salt. Not just any bag of salt. It was a 500g (that's just under a pound to you Americans), bag of french salt that cost $23:00! I was absolutely floored. I didn't think salt that expensive could exist! Am I going to use it for magickal purposes? Hell no!! It tastes amazing, so I'm saving it to use as a spice for special occasions.

Rain water is just plain hard to collect depending where you live, and in what climate. It rains about 2 times a year where I live, and it almost always comes in the form of a short, heavy, storm. As with anything, use common sense. If you can think of a reason you want your gems cleansed with either fancy sea salt, or salt Kosher and soaked in rain or spring water, go ahead, but frankly it makes no sense to me. It just sounds fancy, and costs more. So here's what I do:

When I get a new stone, I put it in a small bowl of regular water & a 1/4 tsp. of regular salt overnight. I then put the gemstones in the window to charge in both the sun, and the moon for a day and night, sometimes 2 or 3. I tend to charge them under a full moon, but if I need the gem before that, any phase works for me. The stone is now ready for use. This process is something you should do in a way that makes sense, and works for you. Not just because you read it in a book, here, or anywhere else. Different books will tell you different methods that work for the author. Try different methods and see what works best for YOU.
 

This depends on how often you are using your gems. If you used a stone for a spell or other purpose, you must cleanse and charge it before you use it again. That's just common sense. But what about the ones you use all the time? For example, you see that big stone in the middle of the photo? That's a smokey quartz I was lucky enough to receive for a gift when I was going through a hard time. Unbeknownst to the person, it's main quality is being a mood enhancer. In essence, it helps take away the blues. I have it on my alter all the time for that reason, and a few others for different reasons. I tend to cleanse & charge them once a month. If you choose to wear a pouch of small gems or keep them under your bed, use your own intuition. Try to get adept at being able to feel the energy that emanates from them. If you do this, you'll have no trouble knowing when they need cleansing and charging.