You know....there could be something to photographing a selection in some harsher light. I'm really loving the colours that come through the bracelet and shine on the background. If I was to have some photographic fun with the items you have, I'd give a little bit more room around the jewelry, add a prop or two and try some direct side-lighting on a couple of them just so see how it shapes up.
I could definitely see the ear-rings hanging off a wine glass. I'd even go so far as to recommend trying some strong side-lighting to see if you can catch some of the colour coming through the ear-rings.
For the bracelet, I think you really need something to support it (like a wrist
) to show-case it better. Keep the white background and give the bracelet more room around the edges of the photograph. I think just laying it down doesn't really convey exactly what it is as it doesn't retain a perfect form when lying there (referring to the second-from last photo).
That last photo could also use some extra room. in the frame. Instead of shooting it as a pano, so a full frame and run it strait with the rule of thirds. I love the colour hitting the background on this one as well.
The first shot is over-exposed and the top-left corner sticks out. Give the background more space, avoid head-on lighting and make sure you don't over-expose it as that washes out the colour of the bracelet. In fact, you might want to under-expose it by 1/3 to 1/2 stop just to help the colour pop.
I think you've got a good start. You just need to have a bit more fun with the shots and play to the light and colour they have to offer. Don't overwhelm the frame with the jewelry...let it command a bit of presence within a space and play around with the rule of thirds and some props that help accent the shape/intended shape when its being worn. In other words, play a bit