I was asked this question by a student of mine last week, and it's been knocking around in my head ever since. Etruscan art, especially architectural art, is made of terracotta: they are rightly famed for their coroplathy. Of course, the Etruscans also sculpted in bronze and sometimes in stone, but the latter does seem to be the exception.

Why was this, when the Etruscans did have access to marble quarries? Did they not know about them, did they just not care about them? Or was it just a sort of "they weren't particularly interested" kind of thing that you can't really explain beyond that.

I'd be really interested to hear your thoughts about this.