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QUESTION
We did a bathroom renovation in 2015. We knocked out a bathroom wall to make the bathroom larger and put in a large Carrara Marble Steam Shower. After using the shower for approximately 3 months, we started to notice that marble on the two outside walls was beginning to turn an orangish color. It has continually gotten darker and darker. We have contacted our contractor and he has sent us back an e-mail asking us to not contact him regarding this problem, that it is not his problem that we picked out Carrara Marble, so therefore, it is our fault and not his. I would like to find out what the problem is and if it can be corrected.ANSWER
ANSWER - Orange or rust like staining in stone can be caused by minerals within the stone or sometimes because the stone is in close proximity of metal. The aforementioned conditions, plus the stone being subjected to excessive moisture, can cause rust staining or also know as inorganic metal stains.White Carrara marbles are known to contain iron sulfide (pyrite) minerals. That is a natural element of the stone, so it doesn’t make the stone defective. Some shipments of these stones contain more iron sulfide than others. Most of the time Carrara marble won’t stain in a shower unless there is metal in contact with it. Although in a steam shower the marble is being permeated with moisture for a prolong time, so it might be staining because of that and because it contains a higher level of iron sulfide. Plus depending on whether the underlying marble substrate is retaining moisture it could be contributing to the problem.
The only way to determine what your situation is, is to perform an inspection that might require removing some stones to see what the underlying conditions are. We can also do a chemical analysis of the marble to determine if it has iron sulfide and to what degree.
Sometimes the staining can be removed when it isn't due to being in contact with metal. If it is a lighter stain that isn't too deep, then a professional stone restoration company can potentially come in and use a poultice or other cleaning methods to remove it. Although over time it may reappear and require additional cleaning. After cleaning the stone if a penetrating sealer is used on the marble, it can help minimize the staining, as long as re-sealing is done on a timely basis.
There are methods for installing marbles in wet areas, using various waterproofing methods, that limits how much moisture the stone will be subjected to. This can greatly limit the likelihood of the marble staining.
7 thoughts on “Why does my Carrara Marble have orange stains?”
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I just installed marble on my kitchen counter and I just seen orange stains on it? How can I remove them?
Rust stains are either caused because there is metal underneath it that has rusted from moisture. Or something metal sat on top of the marble and was exposed to moisture and rusted. In some cases the marble naturally has a lot of iron sulfide minerals within it, and if the marble is subjected to moisture it can develop a yellow/orange like stain. It can be difficult to remove if it is coming from deep into the stone. If it is on the surface it can be polished off. Deep stains have to be treated with a poultice specifically for remove rust stains in marble.
I had new white quartz countertops put in my kitchen. The edge of the cut side looks like it is rusting — it is a dark orangey/yellow color. Do you think the color discoloration could have been avoided by the countertop company? Is this from not sealing in a timely manner, or maybe the caused by their saw? I voiced that I was unhappy with the appearance, and they gave me a polish to use. It did not get rid of the color entirely. Was this their mistake, and they should make it right, or is this just a natural process that happens to white stone?
Thanks!
Quartz countertop should not be showing rust stains, particularly if it is new.
There shouldn’t be anything in the manmade quartz (quartz suspended in resin) that would cause the staining. If there were something in the Quartz then the manufacturer of the manmade quartz should be have a claim filed against them through the fabricator who provided the countertop.
More likely the stain is due to how the fabricator fabricated and installed the quartz top. Sometimes the fabricator will cut a slot on the back of the stone and embed a metal rod coated with epoxy to support the edge from cracking. If they did this, it should have been a stainless steel rod that doesn’t rust. If they installed a steel rod and if moisture gets to it, it will rust .
You stone fabricator should be responsible to remediating the problem.
For the first two years our carrara marble on the shower sill was fine. Now, we have pink spots that seem to be coming up for the marble. Can you help me to get rid of this?
I have the same problem so I hope Donato will answer!
Chances are these are rust spots. Marble naturally have iron sulfide minerals that when subjected to excessive moisture can develop rust-like stains. Chances are the sill wasn’t adequately slopped for water to drain off of it so the water doesn’t sit on it. Marble is very dense and very impervious as to be a classified marble per ASTM C503 the marble can’t have more than 0.2% absorption.
Some marbles just have a lot more iron sulfide than others. Also if the installation wasn’t installed correctly in having drain weep holes plugged or not having an adequate slope not only on the surface of the marble, but also at the underlying membrane it should be sloped to the drain so it can evacuate through the weep holes of the shower pan.
If by chance the stains are only at the surface of the stone you can restore the marble by grinding it and repolishing it, and sealing the marble to minimize the very limited amount of moisture getting into the marble.
If the stains are coming from deep into the stone, you can use a poultice to try to draw them out. The composition of the poultice has to be designed for the type of organic or inorganic stain that you are trying to remove. So there is some trial by error that has to be attempted by testing small spots until you are satisfied with the results.
There are poultices sold online and at stone stores, but it would be best to hire an experienced stone restoration company who has a lot of experience at restore marble with these conditions.