reversible necklace by Anna Gleeson

You can see these and other things, like her Giant Earrings at her blog.

hands play with rubber bands

Rubber bands are hard to transform. They're intriguing, stretchy, and colorful, but their distinct texture and shape makes it difficult to turn them into something more. This is a successful transformation - the results are beautiful.
You can read more about this project by New York based Milev Architects in this deezeen article.