Window sill, check this out.

[Tile Marble Granite]

I just restores this one window sill-tile for a customer of mine, pictures were taken before and after the job was completed.
www.facebook.com/TileMarbleGranite

 

[Spud]

Great job

 

[SJPurdy]

That's more than one tile replaced!!

I hope that there is some good waterproofing on that window sill if the shower is still to be used.

 

[Topshop]

Looks pretty good. The cut tiles at the edges of the windows - if you use some diamond pads (for granite) on the exposed edges you can get some polish.