I guess that depends on how much traffic you think it'll get. A friend of mine just used it in her foyer, and it's lovely.

We have marble I the foyer of our house. It is original to our 1959 house, so it has developed quite the patina. It doesn't bother me at all, it just looks "lived in." People who like marble ooh and aah over it. I'm not a marble person so I covered much of it up with a rug. If you have a formal house and like marble, I'd say go for it.

Be aware that marble is one of the softer types of rock. It will scratch and wear faster than granite or ceramic tiles.

There are marble floors and staircases in countless public buildings like the National Gallery in DC that get millions of visitors a year, and somehow the marble has held up for 80 years. I think your foyer floor will be all right.
Casey

My parents have marble in the foyer of their 1971-built home. It gets a lot of wear, and it is only on the last few years with their walkers sliding across it that you can see subtle scratches.

ETA: if you look for it.

This post was edited by bpathome on Sun, Nov 9, 14 at 21:11

Polished marble floors used in public buildings are regularly maintained. Unless you have it professionally cared for, expect scratches and dulling in a few years. Marble was the "go to" flooring for entrance halls in high-end homes in our area in the late '80s, but seems to have been supplanted by granite since then.