I have a thing for spiney oyster shell.  It screams summer to me!  These coins of spiney oyster are not only orange but also have a bit of the purple in it!  This one sits in a hammered circle of sterling silver and hangs from a sterling silver chain.  Clasp is a lobster claw and you can adjust this necklace from 17"-19".  The perfect summer necklace!  Adds just a nice pop of color to any outfit.  No need to get all matchy matchy!  Wear it with all the colors!