green granite stains

[jc]

I got my new granite countertops Dec 19th. By New Year's Eve, I had my first green stain by my sink on my "lady's dream"- a tan granite with streaks of rust, white, black, etc. Within the week, I had four more mostly round-oval stains on the breakfast bar. Nothing was spilled nor was anything "done" to it. From what I researched, I decided this was metal stain coming from within the granite. My reasoning was that the granite was not sealed properly. The place I bought it from said this should not stain like that and that they've never heard/seen it with this type of granite, nor had their supplier. They tried a poultice on it twice. The "kelly green" stain is a lighter green but still there. They said they can try the poultice one more time. Any theories on why this happened and what do you think is the next step? They state they have been in business for a long time and will do right by me but they are definitely stalling.

[Mark D.]

They are stalling because they are trying to figure out what the problem is. You might try calling the MarbleInstitute of America and asking them. Make sure you know what the name of the granite is.
Mark

[Stone Dude]

if it is coming from within the granite it doesnt matter if it was sealed or not. the sealer allows the stone to breathe, so if somehting is coming from the bottom, up it comes. ive seen green stains associated with copper. when copper oxidzes it turn green . also if they made any repairs to the top before/after it was installed that couldve been the cause. if the slabs were produced by a low quality facility, the resin they used to fill some of the pores could be yellowing or turning green, ive seen this. did they rod the back of the countertop? if they did, and didnt do it correctly this could also be contributing. if indeed they are coming from within the stone, that means they are moving and most likely come right up out of the stone and dissapear. also one more thing. liquid nails has also been known to cause stains with a green tint, if this is what they used to set the countertops, it could also be a contributor. there are a lot of things to take into account to diagnose this properly.

if you can post pictures we may be able to help you.

[stonesmart]

Hey JC,

  Not to attempt oversimplification, but differing shades of green patching is a natural occurring and normal feature of the Ladies Dream (Desert Rose) and Juparana Vyara/ Rosewood materials as well.  It's not uncommon for a granite customer to notice characteristics of their stone after the install such as transparency of the surface with natural light, iridescent flakes or inclusions, color patches, and even background shade changes.  These all are affected primarily by the type of light striking the surface of a granite, and illuminating its properties.
 Is there a chance this might be the case??
  Here's how you can prove whether its natural or not: Make the fabricator show you similar characteristics on the remaining pcs. from your fabrication, or on a same-lot slab.  If they can't, it doesn't belong there!

Best of luck.

Paul J. Michalec
Advanced Stone Tech
Galesville, MS
410-693-7109
stonesmart@yahoo.com
 

[Stone Dude]

  Here's how you can prove whether its natural or not: Make the fabricator show you similar characteristics on the remaining pcs. from your fabrication, or on a same-lot slab.  If they can't, it doesn't belong there!

this isnt entirely true. ive seen one baseball sized spot of quartz in an entire bundle of tan brown granite. as well as one single fossil in an entire bundle of red limestone, and so forth. generally you can compare pieces, but it wont really prove anything.

[david bassler]

CA glue with the accelerator spray (not clean off with a solvent) can react with the ferrous minerals in the stone causing green stains.

A home remedy poultice of Comet and bleach mixed to a paste (1/4" thick and 1/2" beyond stain) and covered with taped edged plastic wrap left to dry for a couple days will pull the stain after several applications.

The other method where caution is advised, but works faster is mix 9 parts hydrogen peroxide and 1 part acetone (the solution can get warm)and apply to a white paper towel (no print on towel) and cover with taped plastic for 2-4 hrs. and remove and wipe area with acetone several times. The acetone may effect the CA glue or other adhesive that was used in that area.

Then poultice with just paper towels and bleach covered with plastic for 24 hrs. Repeat bleach poultice until green stain is gone.

[Mark D.]

If you are trying to lift it as if it was a stain use an alkaline solution. I don't like using bleach on stone because it there is calcium in the stone it could interact with it and hurt the stone's finish. Yes I know that true granites don't have calcium in them, but it is not out of the scope of reason. Try Sodium Hydroxide and water. Keep it on there wet for an hour at a time then wash with water. Repeat as necessary. This will not hurt the stone nor interact with any of the stone's contents. It will lift stains and sealers off of the stone.

Mark