another strange granite question [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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09-19-2004, 06:21 PM
I have Typhoon Green granite and previously had concerns re' rust spots which you folks kindly addressed. Well, at the risk of sounding totally crazy, I have another concern. My granite does have some "pits", and it seems like some type of moisture is seeping into these pits and causing what I can only describe as rainbowish stains (almost like oil-but I know it's not oil) under the glossy top of the granite. I realize things like oil, water etc will cause stains, but when I tested my sample piece of granite the stains presented themselves as just a darker shade of the granite. These rainbow streaks are driving me nuts. Anyone know what they are and what can be done to minimize or eliminate them? Thanks again! :bow:

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09-19-2004, 07:28 PM
Hi paulines:

I’m not a stone expert but after reading your other post I did some snooping around.

Turns out Typhoon Green is exclusively quarried by Cremar S.p.A, a large and well established Italian company in the stone industry. Their main office here in the states is in Dallas, 1-800-220-0966. If our experts here are not familiar with those rainbow streaks, I'd give Cremar a call.

I read in your first post Can rust corrode granite? ( that your granite was sealed. Do you know what brand was used, and how many coats?
Typhoon Green

09-19-2004, 08:35 PM
Hi Pauline :)

I just read your other thread (again), and noted that 511 was used. I don't know if that has anything to do with your situation. As previously posted, I'm not familiar with the stone you have. However, I have run into the "rainbow" streaking on other stones. The only thing that comes to mind is something possibly applied at the fabricators shop. Many are known to preseal (whether needed or not). :bang:

I was able to remove the "rainbow" on my particular stone with a Granite Polishing Compound. It was not a simple procedure. It may, or, may not, be related.

Hopefully, others will chime in on this topic. :)

09-19-2004, 08:57 PM
Not only is John a stone expert, looks like he also much better reader than I. ;)

09-20-2004, 04:54 AM
Thank you Mike and John,
The fabricator was upfront and informed me he had never worked with Typhoon before and was unfamiliar with it. He did excellent work scribing the stone to my wavy walls and seaming it. I believe he has sealed it once. I know it is in need of a proper sealing(s) but I was hoping these rainbow streaks would disipate first, and any moisture in the stone would dry out. Thank you for the picture, from what I understand Typhoon comes in a lighter shade (picture) or like mine, somewhat darker, more olivey. Strange thing- I have an ogee edge and the edge is lighter like the picture whereas the rest of the stone is darker. Thanks for the tip on the quarry, I will follow-up and once again your help is appreciated!

09-20-2004, 05:22 AM
Sorry, forgot to register prior to posting the above. Does Cremar have quarries in Brazil, as I thought Brazil was the CO origin of Typhoon? Another crazy question, please (I'm full of them :crazy: )-As I understand, the price of granite is determined by it's rarity and/or it's difficulty to mine? What would be some examples of an extremely rare granite/similar stone that you have encountered?

09-20-2004, 05:48 AM
Paulines, it could very well be a Brazilian stone. The article I found on Cremar SpA referenced their exhibit of Typhoon at Coverings (trade show). This article said the stone is quarried exclusively by them but did not actually state the country of origin. Additionally I found other pictures of the stone depicting significant variation in overall color, some darker and with more green and bands of "rust" than others.

Steven Hauser
09-20-2004, 08:08 AM
Hi Pauline,

I hope that what I say to you will make sense.

One pertinent question is whether or not this area is subject to direct sunlight for any period of time throughout the day?

To hypothosize,

The material you have is one that has a fair amount of iron in it. This is not problematic exactly except as you have noted it can continue to oxidize.

The material is also a resin treated stone. This process is done to fill in some of the pits and fractures that are naturally present in the stone. This will also deepen the color of the material and as you have noted, the edges appear lighter than the top. There are things the fabricator could do to the edges, and if you and he are interested then have him contact me.

The rainbow streaks you are talking about are probably some sort of oxidation of the minerals and a reaction of the resin to UV rays of the sunlight. To remove them the top of the stone would need to be repolished and then a UV stable resin would be applied.

Pauline, I am not saying this is the responsibilty of the fabricator. So please take that into consideration as you talk to them.

Both these processes are time intensive and require a great deal of skill.

You can ask the fabricator to just fill in the pits, then the oxidation reaction should subside. The rainbow effect will not go away, but it should not increase as fast.

09-20-2004, 12:56 PM
Steven, Hello!
What you are saying makes alot of sense. Let me understand-the top of my stone was treated with resin (is resin applied to the top and allowed to seep into the pits and fissures, as a sealer would do?). The edges are lighter because the resin was "buffed" off, revealing the truer stone color. Somehow, something (water, sunlight etc.) is seeping between the resin and the stone and causing this reaction? The reason I am somewhat suspect of sunlight being the culprit is my kitchen really receives very little direct sunlight (north side of house, shady area), but I'm not ruling it out. The rainbow streaks are definitely originating from the "pits".
This is raising a number of questions in my mind- Is this granite less desirable because of being resinated ?(It was very expensive) Do I follow normal sealing procedures for a resinated granite (and could the sealer used have caused this chemical reaction with the resin). Will filling the pits prevent more damage or is the damage already pretty much done? I have notice a few pits develop in the short time I've had this granite (1 month)-will these pits keep developing and will this become an ongoing problem? I don't know how much support I will get from the fabricator, and should I address these issues with him or the granite yard where the stone was purchased? Is there someone in the Massachusetts area who is extremely knowledgeable about this granite-
Sorry to go on and on, but I'm am concerned (not wigging out totally yet)
Thanks again!!!!!!!!!!!!!!!!

Steven Hauser
09-20-2004, 05:37 PM
Let me understand-the top of my stone was treated with resin (is resin applied to the top and allowed to seep into the pits and fissures, as a sealer would do?)

No, The resin is more of a glue than a sealer. It will do many things that an impregnating sealer does but the salient difference is it is applied to the surface of the stone and then polished off. The only resin that remains is what was able to "penetrate into the stone via pits or fissures.

Many stones have resins applied to them. Both relatively inexpensive stones and rare stones. It is a process used to make the surface more uniform and in many cases to enhance or create a color. So far resin treatment of stones has been a mostly positve process.

The resin process will reduce the stones absorbtive properties but many stones will still need to have a penetrating sealer applied. It is best determined on a case by case basis.

Damage is probably the wrong thought process for this condidtion. Rather, it is a natural condidtion of the material. The rainbow streaks may also indicate that the material has pyrite in it. Both the pyrite and iron will redden when water and oxygen are introduced. The primary difference is the pyrite can have the streaky appearance you describe.

UV exposure is always a good starting point but atmospheric exposure and moisture can produce the effects.

I wonder whether the material has a translucent appearance. If so, then I think that the answer is yes it may continue to occur.

You and your fabricator may need to become better friends than either of you first thought.

Try to take some pichers (pictures) and email them us.

Hope this helped.
edited by author to correct mineral reference

09-22-2004, 02:58 PM
I just wanted to post an update to my situation. I spoke with the Cremar rep yesterday. We discussed in detail the iridescent/rainbow "stains", where they were located, their shape etc. and he relayed this info to his geologist in Brazil. As I suspected, this is not a "natural occurance" associated with this stone. The geologist feels somewhere along the line the stone was exposed to some sort of oil based material (maybe oil from the machines that process the granite), which sat somewhat inert within the stone. My guess is that when water entered the 'pits' next to these stains, the oil separated from the water (right?) and rose to the surface (beneath the resin and/or sealer) exibiting as this rainbow. Am I grasping here? The next question is what to do about these stains and will this be a reoccurring situation. Thank goodness I did not do any further sealing to this granite! I will be happy to keep you all posted and it is comforting to know that to date Cremar is appropriately addressing the situation.

Steven Hauser
09-22-2004, 03:39 PM
Where did the red come from?

How much water got beneath the surface of the resin?

The oil would not solidify then remulsify when exposed to water. So I'm not sure about the premise laid out. I don't see how it would reside inert then because of a small pit liquify.

Stranger things than that have happened with rocks though.

Would you get a mineral content from them while you are at it?


09-22-2004, 04:56 PM
By red, do you mean the rust?
I'm thinking that tiny pieces of stone came loose, causing the "pits" and allowing water to penetrate. The areas in question are around our sink and near the coffee maker (and you know how it is trying to pour water into those things), so they do see more water than other areas of our granite.
Evidently, the mineral comp. of Typhoon green is similar to Golden Beaches? Usually mineral comp. is requested if it's speced for a building, bridge or other structure, Typhoon is new so he didn't have that info handy.