Is it necessary to clear a Tibetan Black Crystal? I have been wearing my Tibetan Black Quartz for about a week now and it has really worked for me. Some trouble I have been having at work suddenly went away the day I got it. I don't want my good fortune to end because the crystal is saturated with negative energy.
I think each piece and the person they work with may be different depending on the situations and circumstances. What I would suggest is this. As long as you feel the crystal is working as it should, cleansing may not be necessary. If, at some point, you feel the crystal energy is fading or feeling denser than normal (which means you also would feel less energetic), then it may be a good time to give it a cleansing.
I have a Tibetan Quartz piece that I truly love. They have amazing energy, don't they? I do not use it on a daily basis, but just to keep the energy moving at peak performance, I cleanse mine in the light of each full moon. Another thing you can do if you like is to simply place it on another piece of quartz in the evening before bed, than pick it back up to wear refreshed the next morning.
All crystals need a good cleansing from time to time. Just pay attention to how you feel energetically, and that will give you an indication of if, and when your crystal companion needs some refreshing too.
Here are some really good articles on cleansing and programming techniques that may help you choose a cleansing method for your lovely Tibetan: