I found this small, smooth, rounded piece of driftwood on a northern California beach. It has nice grain and feels silky to the touch. I'd had the patina'd seahorse charm for a while and the driftwood seemed like a good match. They hang from an oversize brass jump ring on a 24" antiqued brass ball chain.
The driftwood piece is 2 and 1/4" long and 3/4" inch wide. It's actually quite pretty in itself. The seahorse is 1.5" long, with a verdigris finish.