How to Determine the Quality of Marble？

by Julia
Last updated March 7, 2023

Your inspection should not end in knowing whether the marble is authentic or faux. What if your chosen factory provides natural marble slabs, but they are of low quality?

The products that you expect to use for your building projects or offer to your customers will have compromised durability and charm.

To avoid this, we have to know how to look at the quality of the marble. The critical things to check are the following:

uniformity of its appearance;
the evenness of its thickness and size;
the quality of the finish, and;
if there are cracks at the back of the marble.

We will explain each factor in this article, along with some tips on whether the marble is natural or engineered.

Why Is It Important to Know How to Tell a Marble’s Quality?

We always advise the public to partner with or hire the services of a trusted and reputable stone factory, especially in stones as precious as marble. In this way, you won’t have to worry about product outcomes, among other things.

However, determining a marble’s state is still helpful in ensuring that the stone you use can meet or exceed standards, whether in structural buildings or furniture and fixtures.

We can use this knowledge during product quality inspections before or after manufacturing. We will also know how to address a concern if we see a crack in the slab.

Things to Check In Natural Marble

This section lists what you should pay attention to when doing quality inspections on-site. You may list them down or save this article to have a reference while you’re in the factory.

Uniformity of Appearance

We don’t need the marble—a slab, for example—to look exact and equal on all sides. It is only natural that there are swirling colors and veins, all of them blending beautifully.

However, if the marble slab has a yellowish and circle mark for some reason, that’s a stain. In this case, raise the concern immediately.

Another case is a surprisingly flat area on a marble that seems to match the stone’s color but appears faded simultaneously. It’s most likely an etch mark due to exposure to acids. Etch patterns also come in white, appearing as if the stone was bleached.

We can also determine if the factory added an artificial color to the marble by lightly scratching its surface—preferably the back—with a complex tool like a metal knife. If there is no scratch, then there is faux color mixed.

The artificial color won’t last as long as the natural one and can fade after installation, making the marble look bad.

Flip the Marble and Look for a Mesh

Factories may use fiberglass mesh to reinforce a stone, especially if it will travel to a different place. This is so the stone won’t break under pressure or impact we may encounter during transportation.

While using a mesh is not a damaging practice, we shouldn’t have to use it on sturdy stones. Sinodec doesn’t use fiberglass mesh on its slabs, so our marble tables or moldings have guaranteed durability.

Shed Light on the Marble

Another way of checking a natural marble’s quality is to hold it at a 45-degree angle and under the light. If the colors and overall appearance of the marble are smooth and without abnormal marks, then it passes our standard.

However, if you see dull spots with neither etch marks nor stains, those are probably chips. Some factories insert chips in the cracks of the marble to fill and repair it.

While this is not necessarily malpractice, especially if it’s cheap marble, the stone is not sturdy. Especially for high-traffic areas such as floors or outdoor pavements, this type of marble may not last long.

Evenness of the Thickness and Sizes

Whether referring to marble slabs, sheets (for laminated stone panels), tiles, or moldings, all should have equal thicknesses and sizes.

hotel lobby marble border design from sinodec stone

For example, we have the client or their buying agent check or measure the products when we manufacture bulk marble tiles. The machine should smoothly cut the four edges, and the front should be clean with its finish. The dimensions should be even, and the thickness should be consistent.

If the tile has a light slope when we inspect the sides and face, it means the thickness is not even and can negatively affect your project’s quality.

Cracks and Fissures at the Back of the Marble

While we have already flipped the marble and checked for a fiberglass mesh, we also need to check for cracks and fissures.

Hairline cracks on natural marble make it look earthy and antique. That’s why the stone doesn’t need repairs at this point since this type of crack is not detrimental to the quality.

But if you see the back face of the marble and there are numerous cracks and fissures, do not think this is natural. We cannot use this stone in flooring or other high-traffic areas, as it doesn’t meet quality standards.

Level of Porosity

Stones such as marble, granite, and limestone are naturally porous. This means they have “pores” that store fluids like water and compressed air.

While this doesn’t determine the marble’s quality alone (since it’s a natural trait), some marble is more porous than others. If the manufacturer allows it during an on-site inspection, they can pour a small amount of water, and see how fast the stone will absorb it.

Although, we can lessen the porosity by requesting a polished finish and sealing.

How to Know if You’re Dealing Real vs. Fake Marble

If you want a more detailed answer, we have published a separate article that contains the differences between natural and cultured marble.

But to help you determine which is which, check the following characteristics of both variations of marble.

Color – artificial marble is more flexible in coloring. Hence they have colors that do not seem natural such as bright orange.

Pattern – the veins of natural marble are unique and cannot precisely match the veins of other marble, even if it’s the same type and color.

Polish – artificial marble can be shinier due to its gel coating, but it’s not translucent when hit by the light, unlike natural marble

Weight – natural marble is significantly heavier than artificial one, which can be a con for some clients

Cost – while it will depend on the quality of both natural and faux marble, the former is generally more expensive

Do These Standards Apply to Marble Mosaics?

We use surplus materials for marble mosaics that we install on floors, walls, ceilings, and backsplashes.

Since we will need small pieces with different colors to build a mosaic pattern, using slabs is not sustainable and can be costly. We can also use a mosaic mesh that doesn’t determine the product’s quality.

Having said this, it’s quite challenging to apply these standards, but we can still check the following:

design or pattern, if they are proportional and if they follow your requirements;
quality of the color, if it’s too dull or it appears unnatural and;
evenness of the mosaic’s surface.

Conclusion

Determining the quality of natural marble is essential to ensure that the product outcome will also be of high grade. While you may have started a contract with a trusted marble factory, it’s always helpful to know which things to watch out for during quality inspections: