Can Toothpaste Harm Marble Countertops

“I dropped Toothpaste on my Marble countertop. Can it be fixed”  – Theresa M.

We receive many calls and emails each week with a similar question like Theresa’s above. My usual reply is “Maybe, but we need more information”. This question doesn’t really describe the nature of the problem. Is the marble stained? Is the marble etched (polish dull), so we always ask for more information.

In the case of Theresa, the toothpaste indeed did dull the shiny polished surface. We call this etching, and it most often happens on marble surfaces when an acid comes into contact with a calcium based stone like Marble, Onyx, Travertine, and many types of Limestone. Acids dissolve calcareous stone. When an acid comes into contact with calcareous stone (marble, etc.) it burns, eats away the top layer of the stone. This top layer is what reflects light and gives polished marble and other stones it “Shine”.

As noted above in the Google Search, the pH of toothpaste varies significantly from acids (anything below pH7.0 to bases (alkaline) above pH neutral. So the quick take-away is that SOME toothpastes can damage marble surfaces.

Depending on the severity of the damage, many “Oops” moments can be repaired. In the case of light etching, many areas can be improved by using a polishing paste that is made specifically for marble. HMK Stone Care makes a great polishing compound called P21 Polishing Paste.

You use P21 much like you would use a polishing compound for rubbing out a scratch on the paint of your car. I like to use a split microfiber polishing cloth when using P21 because it helps to smooth out the micro-etches or scratches on the marble and helps to get better results.

Squeeze out a quarter sized dollop of P21 on the corner of the cloth, and buff vigorously massaging the paste into the scratch or etched area. Buff area in circular motions and apply more product onto the cloth as needed. Think of the P21 Polishing Paste as a sandpaper paste which is progressively smoothing the etch marks and developing a shine. When you feel you have buffed and polished until you feel like your arm is about to fall off, then buff off any excess with the clean portion of the microfiber cloth. Repeat as necessary.

Many minor surface scratches and etch marks can be removed or greatly enhanced by using the HMK P21 Polishing Paste. For larger areas, we have a larger unit size in a .5 Liter jar.

If you have questions about natural stone, or have a specific problem, please email us with as many details as possible.

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Love Your Granite Countertops ~ Valentines Day Special Discount

We Know You LOVE Your Granite Countertops






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offer good through 2/14/2017

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So Many Stone Sealers…Which One’s Are Good?

There are so many different manufacturers of Stone Sealers, and so many different opinions, so how do you make a choice?

When I entered the dimensional stone trade in the late 1970’s, there was only one company that I was aware of, Moeller HMK from Germany. There may have been other companies out there, but none were  being specified on commercial projects. Every specification I ever saw was for HMK Stone Care. At the time it was imported directly into San Francisco, and distributed throughout North America.

As other products came into the market I would test them against the HMK brand. The most important product was S34 Silicone Impregnator, as it was the Go-To sealer for natural stone. I tested Miracle 511, Dupont StoneTech, Stone Care International, and though these products are good, they just didn’t hold up agains HMK S34 Impregnator.

Fast forward 25 years, and now there are dozens of products available, and to be quite honest, I have not tested every one. We do however get numerous reports back from homeowners and stone professionals complaining that Brand-A or Brand-B failed (not mentioning the real company names) and that they have heard how great HMK S234 (new model number) is. Of the hundreds of clients who have switched from another brand to HMK Stone Care, we have not had a single incident of the product failing, or a complaint that it did not perform as expected. This remains a quite remarkable achievement.

We at StoneCareOnline have been representing the HMK Brand since 1984, and have been national distributors since 1999, and am so proud to have never had a claim of product failure.

The bottom line is, people select brands that they trust, and I have used the HMK Stone Care Products for nearly 40 years, and I trust it! Moeller HMK is a World Wide company, and remains an industry leader. HMK may not be a household brand name, because it is only sold through stone industry professionals, and it will never be sold in the box stores.

We remain committed to assisting homeowners, contractors, and stone professionals with selecting the right product for their project. Please see more at

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I Saw it on the Internet…so it must be TRUE??

cleaning graniteCleaning Granite Counters

About every two years I take the time to search the internet to see if the “Experts” have learned anything about Cleaning Granite Countertops.
I am amazed that there remains very bad advice in the top Google searches on the internet.

Having been in the dimensional stone industry for more than 35 years, I have taken it upon myself to learn about the geology of natural stone, and have traveled to dozens of quarries around the world to learn about the latest fabrication techniques. I have also interviewed industry leaders about resin sealed slabs.

Having reviewed the top four Google results, (see image above) there was some good basic information about cleaning up spills promptly, and using mild dish soap and water for cleanup, but the glaring issue remains the recommendation that people use rubbing alcohol and water, and letting it soak into the stone for several minutes.

Being a contributor to the Wiki-How page, I was able to add a warning about not using too much alcohol, as it is a powerful solvent that can quickly degrade most sealers. Most sites also recommend making a ‘Homemade Daily Cleaner’ using dish soap and alcohol. The problem with using most dish soaps is that it is highly alkaline (pH 11-14) designed to cut grease on dishes. Over time, using a high alkaline cleaner can also break down most sealers.

If you do not want to purchase a Daily Cleaner like HMK P324 Stone Soap, then only use a very mild dish soap with a low pH (near 7.0). Also, it is worth noting that granite countertops are a very good surface to protect against bacteria. See test results HERE.

For a safe and economical option, the HMK P324 Stone Soap is a highly concentrated product. When diluted (1-capful per 16oz. water in a spray bottle) using it daily, just spray and wipe your counters, one liter will last for months.

Please email your technical questions to

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Does Exterior Stone need to be Sealed?

Indian Sandstone needs to be sealed

Image Courtesy of Oz Architects

This project is part of a $30 million project completed in 2002 in Western Montana. The architect specified HMK S39 Silane Impregnator, but the sealer was only used near each joint as a way to protect the stone from the urethane caulk joints, and any smearing or residue. No impregnator was applied to the face of the stone, and not regular maintenance was completed, even though a maintenance plan was part of the architects specifications.

Fast forward to 2016, and with a combination of neglect and a faulty wall flashing, the elements have severely effected the look of the Indian Sandstone. See images below:

You can clearly see where the clean stone is adjacent to the caulk joints that has been protected from the elements since 2002. The HMK Silane Impregnator worked where it was placed. It is very unfortunate that the same product was not applied to the face of the stone. So in a word YES…exterior stone DOES need to be protected with a quality impregnating sealer.

For more information on Professional Grade Stone Care products, please see StoneCareOnline

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Sealing Stone over Previous Sealers – Yes You Can

Deep Cleaner for natural stone surfaces

Deep Clean stone prior to Sealing

We often get questions something like this:

“I need to re-seal my granite countertops, but I don’t know what sealer (if any) my installer used. Can you help?”

The short answer is usually YES, with the following caveat; make sure the stone does not have a topical sealer first (and read below for another qualifier). This is highly unlikely, as most stone sealers for polished surfaces are ‘impregnating’ sealers, or ‘penetrating’ sealers. The operative word denotes that the sealer is absorbed down into the pores of the stone, rather than laying on the surface.

Some types of stone like tumbled travertine, and natural slate, may often have a topical sealer on the surface. You can usually tell this fairly easily by looking to see if there are scratches on the surface, or if there is any noticeable peeling of the coating. Yellowing is a dead giveaway.

For countertops or floors, I suggest performing the ‘water test’ first. Simply take a tablespoon of water and pour it on the surface, letting it absorb for 20 minutes. After 20 minutes, wipe the area dry with paper towels or an absorbent cloth and notice if there is any visible darkening of the color. If the water was absorbed, it will almost always create a dark spot on the surface of the stone. If this is the case, then it is definitely time to apply a quality impregnating sealer.

Here is where it gets a bit tricky…if you wish to use a water-based impregnator, then you may have limited success. If your water test showed the stone drinking up the water, then no-problem, go ahead and use a water based impregnator. We suggest HMK S232 Water Based Impregnating Sealer. If your water test did show some absorption, but the water pooled on the surface then you may want to use a solvent based impregnator.

Prior to using any impregnator, it is best to perform a Deep Cleaning first to remove all topical polishes, waxes, light grease, and grime from the surface. Please see the following directions: Deep Cleaning of All Natural Stone

For optimal results, we suggest using HMK S234 Silicone Impregnator. This penetrating sealer will drive the protectant molecules deeper into the stone than a water based impregnator, because the solvent molecules are smaller than H2O (water).

In case you are interested to see just how well S234 performs, please see how HMK protected a granite countertop from a red wine spill HERE

Using professional grade impregnating sealers will help protect your stone surfaces, and your investment.

If you have technical questions or have a stain that you cannot remove, please email us HERE

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Removing Rust Stains on Granite

remove rust on granite

We have received several emails from people having issues with Rust Stains on Granite countertops particularly around sink areas.


What is not commonly understood is that most natural stone surfaces have some amount of iron minerals in the composition of the stone. Some types have more than others, and some colors have more than others.



If you have a gold colored stone, it is very likely that oxidized iron is exactly what has colored the stone. This occurs in many ways in nature, but essentially Rust leached into the body of a lighter colored stone, thus giving it the tint or color you desired. When these same minerals are continually exposed to moisture (water around a sink) then rust can be accelerate. Further, if you use vinegar to clean the counters, this mild acid (2.4 pH) will oxidize the ferrous minerals an cause rapid staining. In some cases, newly installed granite can begin to exhibit rust stains in months if improperly cleaned using acids.

Fortunately, most rust stains can be removed or greatly diminished by using a professional grade rust remover made specifically for natural stone. We recommend HMK R777 Rust Remover followed by cleaning/neutralizing with HMK R155 Intensive Cleaner. We offer these products in a Combo Kit.

These products are consumer friendly and can remove rust from all non calcium based stone. This product cannot be used on Marble, Limestone, Onyx or Travertine.

For more information about the R777 Rust Remover, please see product information sheet HERE

Note: It is essential that once you remove the rust stains, that you seal your stone with a quality solvent based impregnator like HMK S234 Silicone Impregnator.

If you have questions about your particular stain issue, please email us for professional advise at

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Preventing Rust on Bluestone Pavers

Photo Courtesy of Hamptons Masonry Design

Photo Courtesy of Hamptons Masonry Design

It’s no wonder why Bluestone is such such a popular paving material. When selected and installed correctly, it looks amazing.

Unfortunately, one of the hidden problems with Bluestone is that there are ferrous minerals incorporated into the composition of the stone, which often turn into Rust Spots. These spots can most often be prevented using a few preventative measures.

Most importantly for installers and masons, NEVER use Muriatic Acid to clean cement and grout residue from the stone. Unfortunately, many masons learned that they can quickly and cheaply remove dried cement from stone and brick using Muriatic Acid which costs less than $10.00 per gallon, and it is a very caustic and effective cleaner of cement residue. However, like all acids, it is an oxidizer of metals. It is particularly harmful to Bluestone, as we have had many customers calling us with horror stories about damage.

In many types of natural stone, and Bluestone in particular, rust is inherent in the composition of the minerals. When exposed to moisture, and particularly when exposed to an oxidizer like Muriatic Acid, it accelerates the growth of rust and it begins to leach out onto the face of the stone. (see image below)


In some cases, the rust can be so severe that individual stones need to be removed and replaced. We always recommend the least aggressive cleaners, and progress, if needed to acids to minimize harming the stone, or changing the look of natural stone, particularly Bluestone. We suggest cleaning grout residue with a non-acid cleaner like HMK R155 Intensive Cleaner.

Secondly, and very important, is to protect all natural stone with a professional grade sealer. Solvent based impregnators work best and stop  the acceleration of oxidants. Impregnators come in two types, Invisible and Color Enhancers. For exterior applications, and to get exceptional results I suggest HMK S31 Silane Impregnator. To obtain a deeper and richer color, I suggest using the HMK S42 Color Enhancer. For outdoor kitchen and food areas, for extra Stain Protection, particularly with oil stains, I suggest HMK S244 Color Enhancer Extra.

As a stone professional and contractor using and testing all the leading brands, HMK Stone Care System products (Germany) consistently provide superior results.

If you have a question or problem with your Bluestone, please email me and I will reply within one business day:


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HMK R155 is “Magic Juice”

155-USA-Produktbild-2014-150x150Harry P. from Tarzana, CA called the other day to tell us how marvelous the HMK R155 Intensive Cleaner worked on his marble shower that had a significant buildup of Hard Water deposits. He says the R155 “Works like Magic Juice”

Thank you Harry for your comments, and giving us permission to share your story.

We suggested the following treatment:

  1. Mix a solution of 1-Part R155 to 5-Parts water in a spray bottle.
  2. Starting at the bottom of the wall, spray the wall in horizontal strokes, climbing up the wall until the entire area is covered very well.
  3. Allow the solution to activate on the wall for 15-20 minutes (Same process for countertops) It is important that the surface stay wet with the solution. Spray more as needed.
  4. Scrub area with a medium stiff scrub brush for 5-minutes.
  5. Rinse very well. (Repeat process if necessary)
  6. Allow to dry for 24 hours before applying sealer.

It is important that after you perform a Deep Cleaning of All Natural Stone as prescribed above, that you Protect your stone by applying a quality Impregnating Sealer. We suggest using the HMK S234 Impregnating Sealer.

If you have stubborn hard water deposits, or mineral buildup, or are cleaning up grout haze, the R155 Intensive Cleaner is a very effective (non-acid) cleaner safe for all natural stone surfaces.

If you have a stone cleaning issue, please email us a description, with images if possible to and we will provide expert assistance.

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Remove Etching from Marble


How Marble Etches

Marble is a beautiful and functional surface UNTIL it Etches!

Understand that all Marble surfaces are Calcium based stone that can be easily damaged by Acids and High Alkalies.

The photo above is from Edie Wadsworth’s blog Living in Grace -Living with Marble

In her article, Edie talks about the pitfalls of living with marble countertops. What I have found over the years is that people don’t understand a few simple cautions. Common household liquids can cause etch marks on marble surfaces:

  • Coffee (drips down coffee mug-etch ring)
  • Wine (acid) drips down glass also leaving etch marks & rings
  • Cleaning Products: Windex with Ammonia destroys marble
  • Cosmetics – many contain harsh ingredients

Removing Etch Marks

For minor etch rings and spots, a commercial polishing compound will help restore factory polish. I have used and recommended HMK P21 Polishing Paste for more than 30 years.



Using a soft cotton cloth, or Microfiber Cloth, apply a dollop on cloth and buff into marble etch mark. You must put some force into the buffing action to create enough friction to smooth out the etch marks. Buff off residue with clean area of cloth. Repeat until you are satisfied with results.

For severe marble etch marks that you can feel a rough texture, these will require more aggressive resurfacing techniques. I will follow up with a detailed post at a later date, but for now, please see this LINK


Impregnating Sealers DO NOT protect agains Acids…they work great to prevent stains, but not Etch Marks. You need a physical barrier to protect acids from damaging marble. After protecting marble (and all natural stone) with a penetrating impregnating sealer, you can use the P21 Polishing Paste (like a coat of wax) to marginally protect against etch marks, but you need to re-apply often to help provide protection.

For help with your Marble Etch Marks, please Email us or call 800-380-6881.


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