Dear Rich:
It could be repaired, but it is certainly not a DIY project. Your problem is typical of low-grading slabs of that particular stone (garnet gneiss), but a bona fide stone restoration contractor should be able to do a good job for you.
May I ask you now to please read and e-sign our Statement of Purpose at:
http://www.marblecleaning.org/purpose.htm?
Ciao and good luck,
Mauri
Article ID: 1289
Created On: Mon, Mar 3, 2008 at 3:25 PM
Last Updated On: Mon, Mar 3, 2008 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=1289