I sell some of my jewelry on eBay. I've had the most success selling recognizable brand name jewelry. Even tungsten and titanium rings can bring a good price if they are a recognized brand. Do your research and try to find out the specific name that the manufacturer uses for the item. Sometimes you can find this on the manufacturers website. I've found it best to sell at a fixed price (buy it now) with a "good until cancelled" running time. Sometimes it takes months for the right buyer to come along. Be careful with Tiffany items. They are commonly counterfeited. Usually with Tiffany, I will state in the description that it was found on the beach with a metal detector. Single brand-name earrings sell well as replacements for those that buyers have lost. Sometimes it pays to have a good piece of jewelry professionally cleaned and polished before listing it for sale. My expensive diamonds go to a local jeweler for consignment. He takes a third but has always sold the items for top dollar. Even with his cut, I come out better than if I tried to sell it on my own.