First, let me tell you a bit about myself. I'm a nearly 20-year eBay seller. And, I'm a 35 year veteran in the advertising industry. I've been a graphic artist for that long and have created hundreds if not thousands of visual ad campaigns. Add pro photographer to that resume and hopefully you at least place this in the "credible" file when tabulating the votes. For me, the natural background in the EXACT way you show it is best. This is what most all major product marketers use. The black background is the least desirable. The white is a distant second. Now, it's hard to do this consistently if you're selling items larger than the top of a small table would support. A neutral backdrop running consistently behind, under and flanking your subject properly lit is and always will be the preferred way. Why? Well, to state it simply, the consumer wants and needs to believe that you're being honest in the visual disclosure. ANYTHING manufactured thwarts your effort here. When in doubt in any situation, research the highest-end seller of the thing you're offering. For this item, I would go to Tiffany and Co. You can rest assured that they have spent the enormous amount on researching the best option and are implementing that. Now, there's some contradiction on that site from my recommendations at first glance. They make use of a brilliant illustrated image with a subtle drop shadow and white backdrop. This is entirely manufactured. But, their product is expertly constructed in an art lab. Look at the actual photographed items to see my point. There is a backdrop in there. This is commonly accomplished by shooting the item in a light cocoon with strobes and floods on all sides. A single photograph costs them thousands of dollars. So, don't do what they are doing unless your profit can justify it. It probably can't. Just get as close as you can and reproduce that in perpetuity. It's MUCH easier than it sounds once you figure it out.
