Dear Michael:
There are quite a few black “granites” on the market. None of them is even close at being granite from a geological point of view and all of them with different characteristics. So, which one black “granite” are you making reference to?
That said, the “
whitish/greyish water stains
” that you report having seen sound like efflorescence that could be the consequence of a particular type of black “granite”; or maybe it could be due to the fact that, perhaps, those stones had been sealed.
There are just too many variables involved for me to make any intelligent statement.
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,
Maurizio Bertoli
Article ID: 1058
Created On: Thu, Jan 17, 2008 at 12:45 AM
Last Updated On: Thu, Jan 17, 2008 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=1058