Dear Gail:
Unfortunately your problem is much more serious than it seems, and can't be solved with anything in a bottle. Not to mention the fact that back “granite” can't be technically sealed.
The short end of it is that you've been taken and what you have is not black “granite” at all. It is either maliciously doctored, or it's one of that Chinese black “granite” (Shinxi) that's sensitive to acidic substances.
Either way, the product is not acceptable and you have to demand your money back – no questions asked. And they have to consider themselves lucky if you don't bring the matter to the attention of your local District Attorney that could charge them on Consumer Fraud.
Does the world need marblecleaning.org, or what?!...
May I ask you now to please read and e-sign our Statement of Purpose at:
http://www.marblecleaning.org/purpose.htm?
J
Ciao and good luck,
Mauri
Article ID: 396
Created On: Tue, Aug 28, 2007 at 7:46 AM
Last Updated On: Tue, Aug 28, 2007 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=396