The lighting makes a huge difference! All of the gemstone rings in the first pic are different from the ones in the third.All the rings there were gorgeous, but it is interesting to me how each stone needs different lighting to appear at their best in photos.
In my humble opinion, the showstoppers in the first photo are the emerald ring and the ruby ring, while in the third photo the emerald (which I think is the same one as in the first photo, although the sapphire and the ruby rings are different ones?) does not look as vivid as the blue sapphire.