While the look is "nice," the maintenance, particularly in a shower can be a nightmare. Slate is inherently porous, it is easily scratched, Except for the very highest quality...it easily chips away or "spalls." I've seen some of the cheaper slate actually dissolve when wetted, notably some of the Chinese "slate."

I would seriously recommend that you investigate some of the higher quality porcelain "slate look" tiles. They can look VERY much like slate and have none of the other failings.

Here is a link that might be useful: DalTile

As stonetech wrote, there's a decent crop of porcelain look-a-likes out there.

The natural cleft stuff at HD is atrocious. Recently a neighbor bought several boxes and was having trouble with it. When I inspected the slate, there are five tiles per box, I forget how many boxes he had. But I had close to a 90% rejection rate.

I balanced the slate on my fingertips and rapped the edge with a trowel. With good stone, you get a nice "ring". With most of this stuff it was a dull thud. You could flick your fingernail on the edge and layers would drop off the tiles.

If you have to have real slate, I'd recommend looking at honed slate. Most of the cleft slate is quite poor in quality. To go through a honing process it has to be a much more durable stone. More what we think of when we think of "slate" versus the crappy stuff you see in the store.

I'd have no trouble recommending a high quality slate in a shower, unless it's a steam shower. I don;t recommend any natural stone in a steamer.

If you go with it, just stay away from the lousy stuff.

You might also see it advertised as quartzite. Quartzite is a slate, just different origins. It holds up very well to water.

Fake looks really real. And WORKS so much better. See if you can tell what is real and what is fake in the pic below.

Only the ledgestone and pebbles are natural stone. Everything else is Serengeti Slate by American Olean.

I had slate floors in my master bath, but not walls, with a grout that blended into it well. SUPER EASY for us to maintain. I don't like in the house anymore, so no pics. But for me, who doesn't clean very well, it was easy and I liked it.

I have honed ostrich gray slate/quartzite tile in a powder room (and mud room and formal entry, and eventually will have it in my kitchen). I love it. I sealed it once and it's been extremely easy to keep clean. I haven't used it in a shower, but at least as floor tile it's been fantastic.