I've been watching ebay for leaf and tree rings but haven't turned up anything really unique... until today:
Isn't this ring a little bit wonderful and crazy? The seller calls it the "tree trunk ring." It's 1950's vintage: 7.8 grams of yellow gold topped with .45 carats of ruby. The thing that gets me is that it looks so modern, just like a ring in my previous post. Anyhow, it's not what I'm looking for, but I thought I'd share. You can find it here; it's currently up to about $90 and ends in a little over two hours.