My guess is that it is a coating that needs to be removed from the floor !

--- On Sun, 10/18/09, PBunis@aol.com <PBunis@aol.com> wrote:

From: PBunis@aol.com <PBunis@aol.com>
Subject: [sccpartners] Slate with Etching ???
To: "Restoration and Maintenance" <sccpartners@stoneandtilepros.com>
Date: Sunday, October 18, 2009, 2:03 PM

Can anyone ID this problem? Customer sent this to me and before I go running out to the house, I thought Id get some feedback.
 
Paul Bunis
Xtremeclean Tile - Boston Stone Restoration
Specialty Stone Care
781-793-0700
617-719-8454