Here are a couple of pages from my sketchbook for our current project.
My design is a four fingered ring (not too sure if this is legal) with a little box set on top of it and then a sectioned part off with sapphire stones set into the lid, with a little bit of grass growing from the other side of the ring. THEN have some sort of stone (soapstone is looking promising) around the box. I have been playing with the idea lately, changing the grass with other growing plants, like cress?!