Granite countertops are a luxurious addition to any kitchen or bathroom. Unfortunately, it’s common to find granite countertops turning green!
While this can be quite alarming, it is important to understand why this is happening before taking action.
In this blog post, we will explore the five main reasons why your granite countertop may be turning green, as well as some tips to prevent this from happening.
By understanding the causes and taking the time to properly maintain your granite countertop, you can make sure that it remains beautiful and lasts for years to come.
7 Reasons Granite Countertops Turn Green
1. Iron Oxidation
Granite contains traces of iron which can oxidize over time. When this happens, the iron molecules form a coating on the surface of the granite that can cause it to turn green.
The oxidation process is accelerated by moisture and other minerals in the air, which react with the iron. Over time, these oxidized molecules accumulate and can lead to discoloration of the granite countertop.
For example, if you have a granite countertop near a sink or other water source, the iron in the granite can easily oxidize and cause discoloration.
2. Copper Contamination
Granite can also become contaminated with copper from plumbing pipes or fixtures that are installed near it.
When exposed to moisture, the copper molecules will dissolve and react with the granite, causing it to turn green.
Meaning granite can get copper on it from plumbing pipes or fixtures near it. When there is moisture, the copper will dissolve and mix with the granite. This will make the granite turn green.
For example, if you have a copper pipe or sink fixture near your granite countertop, this could be the source of contamination.
3. Chlorine Bleach
Chlorine bleach is often used for cleaning surfaces, but it can also be damaging to granite.
The chemical properties of chlorine bleach can cause a reaction with the minerals in granite, leading to discoloration.
What this simply means is that the chemical in chlorine bleach can mix with the minerals in granite and make it change color.
When using cleaning products on your granite countertop, always make sure that they are specifically designed for use on natural stone surfaces.
Products that contain ammonia, bleach, or abrasives can cause damage to your granite and lead to discoloration.
4. Moisture and Mold
The most popular cause of green discoloration in granite countertops is moisture and mold. If your countertop is not properly sealed, moisture can seep into the surface of the stone and cause it to turn green.
Additionally, areas with high humidity or poor ventilation can also lead to mold growth on granite surfaces. Mold can leave a greenish residue which causes discoloration.
Mold comes in different colors and has diverse effects on natural stone surfaces like granite.
It’s important to make sure your countertop is sealed and free from moisture to avoid the growth of mold and the resulting green discoloration.
5. Dye Transfer
Dye transfer is another common cause of green discoloration in granite countertops. Due to the porous nature of granite, it can easily absorb dyes from other materials.
The worse part is the dyes can spread throughout the stone and cause it to turn green over time.
When fabrics or rags, food, or other items containing dye comes in contact with your granite surface, they can leave behind a residue that will cause the countertop to discolor.
This is especially common in areas with a high concentration of dyes, such as around sinks or other wet areas where dye-containing products have been used.
It’s important to be mindful of what products you use near your granite countertop, as they could contain dyes that can discolor the stone.
6. The Glue Used
The glue used to install your granite countertop could also be the culprit for green discoloration.
Over time, the adhesive can break down and release chemicals that react with the stone, causing it to turn green.
This is usually common around the edges of the granite countertop, where the adhesive was used to secure it in place.
Cyanoacrylate glues are especially prone to causing discoloration in granite, so be sure to use a high-quality adhesive designed for natural stone.
If you notice any green discoloration around the edges of your countertop, it’s likely due to the glue used during installation.
7. Plant-Based Products
Finally, plant-based products like oils, waxes, and even lemon juice can cause green discoloration in granite countertops.
These plant-based substances contain acids that can react with the minerals in the stone, causing it to change color.
It’s important to use cleaning products specifically designed for natural stone surfaces when cleaning your granite countertop.
In addition, it’s best to avoid using plant-based oils, waxes, and other products that could potentially discolor the stone.
By being mindful of the causes of green discoloration in granite countertops, you can ensure that your stone remains to look beautiful for years to come.
Although green discoloration can occur in granite countertops, it is not permanent and can be reversed with the right care.
Let’s take a look at some ways to fix those pesky green stains and restore the beautiful look of your granite countertop.
Pro Tips: The first step is to identify what caused the green discoloration in the first place. Once you have identified the source, you can use various techniques to reverse the damage and restore your granite surface.
How To Restore Granite Countertop That Turned Green
1. Using Oven Cleaner
If the greening on your granite countertop is ‘green bloom’ or caused by mold growth, one of the best ways to restore it is by using an oven cleaner.
Simply spray the affected area with oven cleaner, let it sit for a few minutes, then scrub gently with a soft cloth or brush.
Once you’ve cleaned off the green bloom, rinse the area with water and dry thoroughly. Repeat this a few times in the affected area, as needed.
2. Re-polish and Seal It Immediately
If your granite countertop has developed green discoloration due to dye transfer, oxidation, or copper contamination, you can restore it by re-polishing and sealing the affected area.
You’ll need professional help for this job, as it requires special techniques and equipment. The process involves grinding down the surface of the stone (usually with a 60-100 grit pad).
It’s important to re-polish and seal the countertop immediately to stop the oxygen in the air from turning the granite countertop green.
3. Using Natural Stone Cleaners
If you prefer a more natural approach, there are several natural stone cleaners available on the market specifically designed to clean and restore granite surfaces affected by green discoloration.
These products contain mild detergents, enzymes, and other substances that help remove the green deposits without damaging the granite surface.
Simply follow the directions on the product label to get your granite countertop back to its original state.
4. Peroxide Poultice
For plant-based greening on your granite countertops, you can use a 12% peroxide poultice to help restore the granite and remove the green discoloration.
Simply mix a 12% peroxide solution with diatomaceous earth until you get a thick paste-like mixture. Then apply it over the affected area, cover it with plastic wrap, and let it sit for up to 48 hours.
Afterward, remove the poultice, rinse the area with water, and dry thoroughly. This technique can help to restore your granite countertop without damaging its natural beauty.
