I've found the perfect medium in "silver clay"  to express my love of the ocean and making jewelry.  Silver clay is a pliable clay that is formed, shapped and dried.   It is then sanded to a desired form and put in a kiln to fire.  It has now become a sterling (94-97%) to fine silver (99%) piece of art.   After a series of polishing and tumbling,  then adding an embellishment of antiquing or hand painted 22k gold....  You have a one of a kind, original piece to treasure.  
Most of my seashells used were found while beach combing through the Caribbean and Bahamian beaches, empty.  No little critters were harmed or killed.