Natural stone in the shower is largely about appearance. It looks great in your shower or shower/tub, or as a tub surround. But if your primary concern in your shower is water permeability and maintenance, then look to acrylic or ceramic tiles.
Fake Natural Stone An Option?
Many tile manufacturers offer a porcelain or ceramic product that looks amazingly like real stone. One such product is Continental Slate Colorbody Porcelain, from Daltile.
From a distance, these rock-looking porcelain tiles can pass as natural stone. But when you get up close and personal, these products -- as technologically advanced as they are -- still look just like ceramic or porcelain.
One problem is that fake stone's texture looks nothing like that of real stone, especially for highly textured materials like slate.
Maintenance Key to Natural Stone
Most any natural stone can be made to work in a shower, as long as it is properly sealed. Unsealed stone allows for water infiltration. Soapstone, due to its slippery talc-like surface, will not accept sealers and is not appropriate for use in showers.
Much of this hinges on personal preference. Functionally, slate can be made to work in a shower; but due to its dark color, slate can feel oppressive in small places such as shower stalls.
Nothing can match the look of real stone in a shower. But be prepared for the maintenance that comes with it.