Are you just starting to sell on eBay? The photo limit is per listing you should not have a problem but that depends on how you bundle the items if you are going to do so. Remember that buyers/viewers have the ability to enlarge or zoom over areas of your photo's so they can get a pretty close up view of a bundle of items or an individual piece.
If you are doing bundles you may want to try a group picture of 10 items as your main photo and then do individual photo's of the individual pieces. If you are doing single item listings you should not have any problems with the 12 photo limit.
I am not sure if you are selling internationally but if you are you may want to familiarize yourself with some countries limitations on importation of jewelry. There was a post on this forum about a seller who had a lot of jewelry seized by, I believe, Russian customs agents.
