Ok, this one shows several defects, first was the choice of red in the bg and the support stuff for the ring showing..but that is not the lighting probs concderning me.  The central gem is a fine emerald and a point source of light would possibly show the returned light from inside the stone better. The side stones at the bottom are dead..no light there.   This is not the best example of what I mean but does give a clue.

Please disregard the dof problems in this particular shot and note the lack of light on the bottom stones, lack of sparkle from the center stone and the still present problems with reflections(black looking areas) of the metal.(Reflections are pretty much under control now, not as in this old shot.)   This was also shot with the down and dirty flourescent with tissure diffuser.  We do not have a photo set-up. It is make do as you can.

Thanks for bearing with me on this thread!         Tom.