I read once that you can purify/charge a crystal by placing it into a Tibetan Singing Bowl (TBS), while it rings. I've done water, breath and sunlight in the past to do this, but, I now own a TBS, so I gave it a shot, with an Arkansas quartz, double terminated crystal, with an Isis head and a small in and out crystal.
The feeling of the crystal afterwards, was pure. Seriously pure. Sort of like the feeling of deep space, everything and nothing all wrapped into one.
Nice technique that seems to work well!!!
My advice would be to keep the tip away from the sides of the bowls, so it doesn't chip. At times, the crystal itself seemed to be vibrating adding to the bowl's tone, in a way the mallet I was rubbing around it couldn't do. Cool!