Is Granite Porous?

Date: November 18, 2020
Author: Jon Smith
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A piece of granite or another stone may seem really solid to the blind eye; however, once you put it under a microscope, you will see that granite and other natural stones have thousands of microscopic pores. These pores are created when the granite is formed deep within the Earth’s mantle. Tiny grains of minerals and organic matter are placed under intense pressure and heat to create natural stone.

Because granite and other natural stones are made up of individual crystals or grains that are compressed together, tiny pores are found between each crystal. What do these pores mean to you?

These pores allow liquids and oils to be absorbed into the stone. Luckily, there are several things you can do to keep your granite countertops looking great for many years to come. There are sealers that can prevent absorption and thus prevent stains in your kitchen countertops.

Understanding the Difference Between Porosity and Permeability

Many people use porosity and permeability interchangeably; however, they are different. Let’s look at the definition of porosity and permeability to help you understand how they can impact your granite countertops.


Porosity is the ratio of the open space in a natural stone to its solid volume. Igneous stones like granite typically have a lower porosity level than metamorphic and sedimentary stones. This is due to the minerals found in the different types of stone.

The tiny grains may be compacted tightly; however, they will not fit together perfectly, which means there are gaps in the stone.


Permeability is the stone's ability to transmit fluids into the stone. Fluids are transmitted in two different ways – the capillary structures and pores found in a stone. One great example of permeability can be seen in a piece of marble.

When you look at a piece of marble, you will see veining (capillary structures). Although the pores are too small to be seen by the naked eye, the variation in color in granite can help you understand how the pores of granite are formed.

A natural stone can be both permeable and porous. When a stone is both porous and permeable, liquids can easily absorb into the stone. This means that water, oils, and acidic liquids can be absorbed. Water and oils can discolor or stain your granite countertop while acids can weaken and even dissolve the stone, causing it to break, crack or fracture.

Granite is one of the least porous countertop materials, which makes it a great choice for countertops. However, it is important to remember that granite can still absorb liquids. This means that granite is at risk of staining or etching. Therefore, it is important to know how to properly care for your granite countertops.

How to Reduce Granite’s Porosity

One of the best ways to protect your countertop is to use a sealer to reduce the porosity of granite. Sealers form a barrier that helps prevent the granite from absorbing liquids, oils, and food particles.

There are numerous sealers on the market; however, there are two categories of sealants on the market – topical sealers and penetrating sealers. Let’s take a look at the two different types of sealants. Granite Gold Sealer is one of our favorites.

Topical Sealants

Topical sealants like Stone Care International Granite Sealer is easy to use and helps protect your countertops. A topical sealant sits on the surface and prevents liquids from soaking into the countertop.

This type of sealer prevents etching and scratching; however, the sealant can be scratched and need to be resealed. Moisture can become trapped within the stone. Topical sealants typically need to be reapplied every six months to one year.

Penetrating Sealants

Penetrating sealers seep into the stone and fill the holes from within rather than just the surface. The penetrating sealer prevents liquids from being absorbed; however, it does not protect the surface of the countertop from scratches.

A penetrating stone sealer like Miracle Sealants Impregnator Penetrating Sealer allows the stone to breathe because it forms a chemical bond with the countertop that will last for years to come.

Granite is a natural material that contains different types of minerals. These minerals are compressed together deep within the Earth. The different materials do not fit together perfectly, forming pores. These pores allow liquids, food particles, and oils to enter the granite, causing staining, etching, and damage.

When it comes to natural stone countertops, sealing is a must. A sealer helps protect the structural integrity of your granite countertop. Both topical and penetrating sealants are easy to apply. In fact, many homeowners opt to use a penetrating sealer along with a topical sealer.

This provides the homeowner with the best of both worlds. In order to ensure the effectiveness of the sealants and providing you with the best protection, you will need to test your countertop’s porosity using a water test.

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About Jon - Website Owner

Jon Smith

Hi, my name is Jonathan Smith. I have been in the granite business for many years and have worked my way up from an installer helper to an installer and then a countertop business owner. 

I started my countertop company with very little and grew extremely fast because of my knowledge and helpfulness. I started this countertop resource for 1 main reason. That reason is that there are no countertop websites with all the correct information and none of them are from an industry expert like myself. 

I am still in the trade every single day installing countertops, educating people on the type of material they are using for their homes, and making people's dream kitchens a reality.
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