Stain (?) on Jet black granite

Hi, I installed a countertop of Jet Black granite tiles (bought at our local Ace Hardware store) a couple of month ago. After just a few weeks, we had several stains (lighter, grayish tone), but we don't know what substance could have caused it. Not knowing much about granite, we tried to remove the stains with a stain remover (paste that is left on for 24hours) bought at our local hardware store. That only had the effect of causing the stone to gray wherever it was applied and made the stains even lighter, so we now have two types of stains. Reading some of the advice on your forum, we then tried to strip any possible sealer with Methylene Chloride, which did not do anything for the stain. We did this only in some test spots and noticed that it definitely took off the sealer, as we can notice a different in the way water is absorbed on those areas. Are there any other remedies we could try? Will a professional be able to do anything about these stains? Thanks in advance.

Dear Reinold:

Let's start by saying that a stain – a real stain – is always darker than the stained material. If it is lighter, it's either a mark of corrosion created by an acid (etching), or a caustic mark created by a base (bleaching). There are no known exceptions to this rule.

Since stone can't bleach, what you have are marks or corrosion (etch-marks). The thing is that black "granite" should not etch... So what's the deal?

The deal is that your tiles have been maliciously doctored by the factory to make them appear black, while in fact they are dark gray. Anything pH active that you spilled on your tiles peeled off the black "shoe-shine" and the gray is the true color of the stone.

It's a criminal activity that's going on for years and counting.

Go back to the store you bought the tiles from and demand your money back or else you will bring the case to the attention of the local D.A. on consumer fraud charges.

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,

Maurizio Bertoli

www.marblecleaning.org – The Only Consumers' Portal to the Stone Industry Establishment!

Article ID: 679
Created On: Tue, Oct 23, 2007 at 8:10 PM
Last Updated On: Tue, Oct 23, 2007 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]