that is very common with crystalized floors. i think it has to do with the steel wool rubbing the grout, you will also see it on terrazzo where it his the metal strip.

From: Roger Konarski <qm144@yahoo.com>
To: Stone and Tile PROS Technical Support <sccpartners@stoneandtilepros.com>
Sent: Thursday, November 29, 2012 7:14 PM
Subject: RE: [sccpartners] K crystallizing system

While we are the topic of crystallization. I recently have been asked to look @ two commercial jobs that are currently be maintained by that system,  They both have the dark grout lines. How do you get rid of the dark grout lines?

From: Fred Hueston <fhueston@gmail.com>
To: Stone and Tile PROS Technical Support <sccpartners@stoneandtilepros.com>
Sent: Thursday, November 29, 2012 6:05 AM
Subject: RE: [sccpartners] K crystallizing system

Not sure but the inventor of crystallization is a company in Spain named Koor and Cleiver....this may be theirs

On Wed, Nov 28, 2012 at 7:52 PM, Pat Staples <cpstaples@msn.com> wrote:
Did anybody ever hear of a K crystallizing system, if so who's system is it
 
Thank you
Carl Staples
Classic Marble & Stone Restoration
Marblerestore.com
610-356-4100



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