Stains vs Etch Marks

Very often in the stone restoration business we get calls regarding stains in marble countertops or floors, caused by wine, vinegar, juices, bathroom cleaners and other liquids.  For the most part if you blot up the liquid when it spills then it will not have time to stain the marble.  However when the area dries you may see that the finish on the marble looks different in the area of the spill.  What Happened? Well although the liquid did not stain the area, the acidic, or in some cases high alkaline, content caused a chemical reaction with the calcite in the marble.  This is known as etching.  This reaction is similar to ones you may have gotten in chemistry class by placing bits of shell in a beaker or test tube, and introducing HCL ( Hydrochloric Acid) the shell will bubble and fizz until it is completely gone.  There are several methods available to a stone professional to correct the etched area.  From simply polishing the affected area if the etch is not too severe, to diamond honing until the surface is perfectly smooth again.  So there is no need to worry about your stone, the beauty of natural stone is that most damages that occur can be corrected and your stone can look as good as new.

Stone Needs to Breathe




“Your stone is breathing…”

Quite a statement but in a way natural stone does breathe.  Stone has an internal structure that is not totally solid.  There are two physical properties found in stone, or is in capillary structures that are interconnected structure size and orientation of these networks affect the degree which moisture can migrate by capillary action through the stone. Moisture migrating through natural stone is called “moisture vapor transmission”.  For example, moisture present in the ground can be wicked or drawn up into the stone by capillary action. the porosity of the stone - that is the amount of voids in the stone and its permeability a  network of pores move the moisture vapor is like a sponge through the stone.  The vapor is then released into the atmosphere.

Granite for example during the formation process was under high pressure and temperature.  This allows for very little open pore space the grain sizes of feldspar Quartz etc. can increase porosity during the cooling process of the stone after high temperature the quartz grains can contract more than half their size.  This allows for extensive cracking around the quartz so it’s more of a fracture than a poor throughout stone.

Marvel during the formation process takes place by an increase of temperature and pressure.  The original minerals of the stone merge to form smaller crystals to larger crystals.  These are then reformed into a new texture.  It is during this process that micro pores develop between the grains.  Mineralogy in the degree of metamorphism of the stone causes the size and shape of pores in marble.

Sedimentary stones such as limestone and travertine, consist mostly of fossilized material found in ancient sea, lake and river beds.  Pores develop as a result of compaction of various minerals organic material secondary older stone from the area in sediment.  Due to the process an unlimited variety of pore sizes and shapes are prevalent in sedimentary stone.  Granite and marble are generally low in porosity while limestone is considered highly porous.

When the pores and capillary structures are interconnected, the result is permeability.  Liquids can be absorbed into the interior of the stone or move from the substrate by this capillary action of pores and fractures.  Permeability may be greater in one direction or another depending on pore size, shape, and the distribution of fractures within the stone.

So what happens if a stone can’t breathe?


What Sealers Actually Do

Sealer is a term used by stone craftsman to describe a stain deterrent that is applied to natural stone is "sealer". It's a general term that most consumers can relate to, and understand why it needs to be applied. In actuality the correct term is impregnator, however impregnating sealer, penetrating sealer seem to be used interchangeably. The name of the substance pretty much explains what it does. It penetrates into the stone and seals, but it seals without clogging the pores like a topical coating does. Instead an impregnator merely coats the pores of the stone allowing moisture vapor to escape, and letting the stone breathe. I know I know this has been said a million times, and most restoration professionals could recite it in their sleep, but do they actually know what occurs to make the impregnators work? Well in most cases only partially.

Go Green
Saturday, 26 November 2011 07:39


Go Green!
The natural process to polish your marble.
by Glenn Kiyan Of Advanced Stone Restoration Hawaii
edited by Steve Patrick

In an earlier article, "Crystallization of Marble - The bad, the worse, and the ugly", I described the adverse effects of marble being polished incorrectly. In this article the correct and ecological choice of polishing marble is explained.

Polishing of stone is to attain a high shine by use of fine abrasives. Most craftsmen will use diamond abrasives to resurface an area and make it scratch-free and to remove etch marks.

To acquire a true polished or honed surface, the imperfections must be grinded or sanded to the level of the damage. Depending on the depth of damage will reflect on how many steps will be needed for the repair.

Below are all the steps listed for a full natural stone restoration. Most jobs usually require the last two steps of honing and polishing. Only an experienced specialist could recognize the proper order needed to achieve the desired finish.

Step 1:
De-lippage & Flattening: This process is usually recommended when the stone was was installed incorrectly. Lippage is the term given to uneven tiles that are set higher than one another. De-lippage/ground in place is recommended when the lippage exceeds 1/8 of an inch or if one desires to have a completely flat floor

Step 2:
Grinding: A very aggressive process using metal-bonded and diamond grits to remove deep scratches and lippage. Performed by using a heavily weighted floor machine with water, this process is typically dust free. The goal is to flatten the floor.

Last Updated on Wednesday, 30 November 2011 22:17

Contact Us

Christopher Soderlund
Stone Specialist

Boston Area

(508) 734 - 0435

Cape Cod

Give us a call to have your natural stone professionally evaluated today.


The Stone Repair Network is dedicated in providing quality restoration, repair and maintenance through a network of stone repair professionals. Our network is committed to the education of both the consumer and the industry in the advancement of stone restoration.

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Case Study 1 & 2

Marble Floor Polishing

Marble flooring is one of the best ways to add elegance to any room. However, as is with most materials, proper maintenance is required to keep your marble floors looking beautiful.

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Marble Counter Repair

Marble countertops and furniture are a stunning focal point of many bathrooms, kitchens, bar tops, and display areas. However, when marble is used for these areas, it does require maintenance to keep it looking beautiful. Learn more...

Case Study 3 & 4

Granite Polishing

Granite Face Polishing is an art that few have mastered. When granite is scratched, etched, or worn there are several methods and steps required to refinish, and re-polish to achieve a perfect result.

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Granite Etch Repair

Stone Seal can repair etch marks on granite.

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Case Study 5

Terrazzo Restoration

Before calling Stone Seal, the owner of the terrazzo floor had an acrylic coating applied. As is the case with most topical coatings, dust, dirt, and sand were trapped and consequently ground into and scratching the floor.

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Case Study 6

Soap Stone Restoration

Soapstone utility sinks like the one pictured are very common in older homes in New England. Over 100 years of use, for many different purposes has left these sinks in terrible shape. Chipping, Paint, Oils, Grease, dirt, tarnish and neglect have covered up, and damaged the natural beauty of the Soapstone.

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