Thanks for the comments guys!
Ivox what do you mean by
" .....with a fill larger fill plane --- remember that smaller emitters will create more distinct caustics"
Do you mean for me to use small emitters? If so how would that create a larger fill plane? Here is a photo of my setup with fill lights
In that scene I have a long rectangular emitter in front of the ring and a sperical emitter behind the ring. Do you think I should add other smaller emitters to the scene?
I will try to figure out HDR's I was a bit concerned that I would have leaves or something like that reflecting in my jewellery so I haven't bothered with it yet.

. But I am inferring from reading all of these posts that HDR's are the way to go. Thanks
Cary