How To Clean Onyx Countertops: 5 Steps (Do This!)


Onyx offers a stunning look to countertops, showers, floors, and is even used to make jewelry. This natural material requires maintenance and proper care to promote durability and longevity, especially in high-traffic areas such as your countertops.

To clean your onyx countertops:

  • Wipe down surfaces with a neutral cleaning solution, removing all excess liquids
  • Scrub off stuck debris with warm water and a soft toothbrush
  • Eliminate any cleaning residue
  • Dry the surface thoroughly
  • Seal and polish the surface to maintain it and repair scratches

How Onyx Porosity Affects Cleaning 

Onyx is a natural stone that can easily absorb liquids due to its porosity. This means that when spills happen, they should be blotted up immediately to avoid staining or damage to the surface. 

Furthermore, onyx countertops can absorb acidic or alkaline solutions, such as vinegar or oven cleaners. These can damage the surface by leaving permanent stains or etching it. 

Scouring chemicals or abrasive cleaning tools can leave stains and scratches. Due to its translucent nature, onyx can more readily show these defects.

You must choose a mild pH cleaner that will not harm the onyx surface or wear down the sealer prematurely.

If your countertops repeatedly absorb moisture, lighter surfaces may start to yellow, or darker surfaces will show uneven patches of color. Sealing can help to prevent this.

Sealing onyx countertops with a food-grade sealant can help prevent absorption and staining, increasing the surface’s durability and longevity. 

Generally, you should seal the surface twice a year to every three years. Usage, wear and tear, and lighter colored countertops need sealing more often.  

Acceptable Cleaners For Onyx Countertops

While many homemade cleaners, including vinegars, are effective on a variety of surfaces, you should only clean onyx with pH-neutral solutions (around 7). 

If commercial product labeling does not state the pH level, do a quick search online for more information, or you can test the liquid with pH strips.

This table gives examples of what you can and cannot use for cleaning onyx countertops:

Acceptable for UseDo NOT Use

  • Soapy water: dish detergent (1-teaspoon) and warm tap water (1-cup)

  • Commercial stone cleaner designed for use with onyx


  • Glass or window cleaner

  • Oven cleaner

  • Drain cleaner

  • Multi-purpose kitchen cleaners, such as Pine-Sol

  • Bleach

  • Powdered cleaning solutions

  • Melamine foam (Magic Eraser)

  • DIY cleaning solutions

How To Clean Onyx Countertops

What You Need

  • pH neutral cleaning solution
  • Paper towels, tissues, or soft cloths
  • Soft toothbrush

1. Wipe Down Surfaces

Clean up any spills immediately, by blotting. Avoid wiping motions so that you do not further embed spilled liquids into the surface. Use the cleaning solution to blot up any remaining liquid from spills. 

Use soft cloths or paper towels to avoid scratches or swirling, which can occur with abrasive materials.

Apply cleaning solutions to the paper towel or soft cloth, and not directly to the countertop surface. This helps prevent over-saturation and the absorption of moisture and liquids. 

If you are cleaning a spill-free countertop, it is okay to use a light wiping motion.

Use additional dry paper towels or cloths and continue to wipe down the surface until all moisture has been removed. 

2. Remove Stuck Debris

After wiping down the surface, if there is any crusted-on debris, you can lightly scrub this area with a soft toothbrush. 

You can loosen the stuck material by using hot tap water; apply the liquid with a paper towel or soft cloth.

Apply the cleaning solution to the toothbrush, not the surface, and concentrate on scrubbing gently only on the affected area. 

3. Eliminate Cleaning Residue

Use warm tap water only for this step. 

Dampen a new cloth or paper towels and wipe down surfaces to remove any residue from the cleaning solution. 

Alternate with dry cloths to remove any sitting moisture. 

Repeat this process at least one more time.

4. Thoroughly Dry The Surface

Take another clean cloth or paper towel, and thoroughly dry the entire countertop, using a blotting or patting motion. 

Leaving any liquids on the surface can allow the stone to absorb them and leave stains or watermarks.

5. Maintain The Countertop

You must maintain your onyx countertop. 

Incorporate the tips below into your daily and yearly practices.

Prevent Spills

Place down a protective mat, wax paper, cutting board, trivet, and so on when preparing food. 

Put a coaster underneath drinks. 

If you spill something, blot it up immediately as described above.

Seal The Surface

Regular sealing will keep your countertop in good shape. This slows down the absorption rate of the natural stone. 

Make sure that any commercial products used for sealing are food-grade and formulated for use on onyx. This natural stone does not necessarily use the same sealing products that are used on marble or granite.

To apply sealer:

  1. Put the sealer on a dry cloth and rub it into the stone in circular motions.
  2. Let it dry according to packaging instructions.
  3. Buff it with a clean cloth.
  4. Let the surface dry for a minimum of 6 hours before use. This allows the sealer to soak into the pores.

If you choose not to do this on your own, professional countertop installers can seal it for you. Make sure you hire someone that has knowledge and experience with onyx stone. 

Repair Scratches

Scratches unfortunately are bound to happen with the use of an onyx countertop.

You can minimize the risk of scratches by taking care to not drag things across the surface. Use trivets, placemats, and so on to prevent scratching.

A professional can buff and polish these scratches away or you can do it yourself.

Use commercial products that work specifically with your onyx countertop. Consult with a knowledgeable professional that installs this type of material to determine what to purchase.

Generally, you will use a polish, buff pad, and paste wax. Follow the instructions on the products for applying them:

  1. Apply the product to the scratched area in a circular motion.
    • Remember to apply the product to the buff pad or cloths and not directly to the surface. This ensures that you do not use an abundance of products which will result in heavy absorption and an uneven colored appearance.
  2. Wipe up excess product with a clean paper towel or cloth.
  3. Repeat until the scratches disappear.
  4. Clean the area with water and a clean cloth. 
  5. Dry thoroughly and reseal the surface. 
    • You will likely need to wait 12 hours or more before using the surface again to allow the products to fully cure on the surface.

In Conclusion

Onyx offers an attractive focal point in kitchen areas installed as backsplashes and countertops. 

To retain its beauty, you should always use care around onyx – and other countertop surfaces – by protecting them from scratches and cleaning up spills immediately. 

Clean the surface with a neutral cleaner, such as a soapy water solution. 

Apply a sealer that is formulated for use on an onyx countertop. This will help protect the surface from liquids and promote its longevity and beautiful aesthetic.

Lisa Burlison

Lisa is a freelance blogger, literacy specialist, teacher, and self-published author with a vast DIY experience. When she’s not writing for PlumbJoe, Lisa enjoys testing homemade cleaners and doing repairs around her home. Her other hobbies include birding and bicycling.

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