@Eleanor: Thanks for the post and sorry I missed responding earlier! Shapeways has been great to work with.
I made this pendant design for a gift, based on a chalice motif. It was small enough to print in silver for pretty reasonalbe. They have three silver options: one super polished, one untouched after printing, and one that is lightly polished. This one is the last option and it came out pretty smooth. The only issue is that I modeled the chain / lanyard hole pretty small, and it did not come out as a full through-hole. Funny how things always look huge in CAD. 
I still need to get a chain for it.
I could not resist trying it in their “polished gray stainless steel” option too. Curiously, the chain hole on this one is fine. The surface is definitely rougher with the print lines, but the edges are crisper than the silver one too, which gets a little bit of the water-worn rock effect. This is all probably because the thing is tiny (see the third image).