Dear Steven:
Without knowing what kind of marble you have I can't answer your question.
If nothing happened to your stone, it could just be the “nature of the beast” (certain marbles do have so-called “dead spots” throughout their texture that will not polish as the rest).
If instead some “accident” happened that caused the dull spots (acid etching), then a good-quality Marble Repair Kit could do the trick for you.
Unfortunately, without the information about the type of marble you have I can't give you a more precise answer.
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: 770
Created On: Sat, Nov 10, 2007 at 4:06 PM
Last Updated On: Sat, Nov 10, 2007 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=770