Restore Slate Tile in Shower
I have slate tile in my shower (mistake). Even though the tiles were sealed, they have become discolored and look "weathered".
Is there a way to restore the tile to its original glory? See pictures attached.
From looking at your photos, what I would do is clean the slate tiles with a tile cleaner that is acidic.
CLR or Lime Away work as well as any acidic tile cleaner.
Use gloves so you don't harm yourself and also allow the acid to eat away the calcium. Then use a razor blade to scrape the calcium away.
I would do this over and over again until you've cleaned the calcium off the slate tile.
It's tedious and not fun, but the only way I know of cleaning the calcium from the slate tile.
I hope this helps.