Interesting combination. To be honest, I prefer lots of your other work - but I think this is pretty good for an experiment. This jewel also looks rather flat. This time I can definitely make out the fractal in it, but it is almost too much and not blended in quite enough. I don't know. Other people will likely differ. Just a thought.
The background is lovely - like a multicoloured fractal candyfloss, almost, or perhaps a polished rock with fiery veins of quartz. I agree with CFR about the jewel, though. Maybe it would work better if the contained fractal looked a little different (in shade) from the background. It could also be slightly distorted (if that doesn't blur it too much). The shape of the jewel itself is a touch on the dark side, without much graduation. I don't know that I would do anything like as well, so these are just the thoughts of a viewer! I love the energy of a lot of your work.
- cfr