You wouldn't think of hard-working furnishing like shelves as artwork, but NYC interior designer David Netto pulled it off with these artful shelves. They're a beautiful composition in and of themselves...

Dark wood floating shelves intersect a shadow box that's been backed with marble. The result is half sculpture, half storage. These are found in the kitchen of a 5th Avenue apartment designed by Netto.

One more look at another shelf-or-art object in the dining room of the same apartment:

These appear to be more of the "art" variety, maybe minimal sculpture? Nonetheless, they could easily be shelves. The boundary is blurred like this all over the apartment. See the rest of the home at David Netto Design.