Hunting down a gorgeous antique aquarium could take some time (try eBay, flea markets, and vintage shops), but any glass vessel with a flat side brings crisp clarity to gnarly organic items. Fill the vessel less than halfway (much of the beauty is in the negative space), and arrange the biggest pieces on top. Blow away dust occasionally with a hair dryer set on cool. If you have a constant influx of rocks or shells, stash piles in old peanut-butter jars and tuck them away on a closet shelf. Shell collection and vintage aquarium courtesy of Linda Rodin.