Two Reasons Why White Marble Can Rust and How to Prevent It

Many homeowners in NY have asked us: Is it true that my marble is rusting? What are those brown or yellow spots in my marble? If you’ve noticed discoloration on your marble surfaces, you’re not alone. White-colored marbles, such as the Calacatta and Carrara families, generally contain iron deposits. This makes them susceptible to rusting and developing yellow stains over time.

Why does this happen? There are two main reasons:

1. Metal Deposits: White marble naturally contains iron deposits, which can oxidize when exposed to moisture and air, leading to discoloration, often appearing as brown spots in marble.
2. Improper Sealing During Installation: If the stone is not sealed correctly—especially in areas where holes are drilled, like around sinks—dirty water can accumulate over time, seeping into the stone and causing oxidation in marble and rust stains in marble.

How Easy Is It to Get Rust Stains Out of Marble?

The short answer? It’s not easy at all. As someone with 20 years of experience and dual stone certifications, I often refuse rust stain removal jobs because I simply cannot guarantee 100% results.

Even if I attempt it, I never know how many times I’ll need to return to a customer’s home to continue working on the stains. Rust in marble can be stubborn and unpredictable, making it one of the most challenging issues to tackle with marble surfaces.

As a Consumer, What Are You Left With?

If you’re just installing marble or have started noticing those pesky yellow rust stains, sealing your stone is one of your best moves. But here’s the tricky part—sealing has to be done correctly, and it’s not as simple as most people think. And even then, is it a 100% guarantee? Unfortunately, no.

Your second option? Try using a poultice kit and take matters into your own hands. I recommend Fred Hueston’s kit. Why? Because Fred Hueston has been in the stone business for a long time. He’s incredibly knowledgeable and has developed a kit that’s been tested by professionals and homeowners alike.

Can I Promise 100% Recovery?

Nope. But here’s why you should consider doing it yourself—if I were to handle it, I’d need to come back multiple times, which can get really expensive. And even then, I still can’t promise perfection. With a poultice kit, you can work on the stain overnight and reapply it as needed without the added expense.

But Here’s the Catch…

If you have a shiny, polished marble—especially white marbles—the polished surface can actually work against you. The shine comes from the pores being closed, which helps keep moisture and water out to some degree. But it also prevents the poultice from penetrating and doing its job effectively.

For the best results, it’s ideal to remove the shine and open up the pores of the stone to a matte finish. Once that’s done, apply the poultice, clean, and then repolish the stone. However, honing the marble to a flat finish and bringing it back to a polished shine is a job best left to professionals who understand the process—especially when it comes to shower walls, where this issue is quite common.

The Real Challenge with Rust Stains

The biggest problem with grinding the marble to remove the surface is that you never know where or how the metal deposits run through the stone. This uncertainty makes it even more difficult to achieve a flawless finish.

A Different Perspective on Marble

At the end of the day, marble is a natural product. It’s beautiful, timeless, and, like all natural things, it will develop a patina over the years. Cultures with a long history of using marble, like those in Europe, have come to terms with these natural imperfections and embrace them. They let the marble age gracefully, appreciating its evolving beauty.

In the U.S., however, we often obsess over perfection, sometimes losing sight of what marble truly is. It’s a natural, healthy, and durable product—if you ask me, it’s alive, with its own energy and dynamics.

Over time, I’ve learned to embrace traditional and natural products and appreciate the unique charm they bring. Sometimes, all it takes is a shift in mentality to truly appreciate the beauty of marble in its natural form.

By Bob Baniasadi, Certified Stone & Tile Inspector