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I did jade on a model I just finished, but it's topless so be cautious...
I used the RMS colors forest green, grass green, jade green, and white. If you're going to do jade as a varied surface, Zaphod's is going to be more helpful to you than mine. You'll need a firm grasp of how gems react to light (the painting clinic has a good tutorial about gems in general), and you'll also need to have a clear light source in mind, so your highlights will all look like they are originating from the same place, otherwise, the illusion won't work.
Good luck!
/ali