I would say hard water deposits
On Monday, February 24, 2014 4:18 AM, Pat Staples <email@example.com> wrote:
Can also be imbedded with soap film
Classic Marble & Stone Restoration
Subject: RE: [sccpartners] Bad Case
Date: Sun, 23 Feb 2014 22:08:38 -0500
Difficult to tell, but it looks like those tiles are severely etched. In which case I would say they are currently or did at some point use an acidic cleaner.