The Age-Old Appeal of Patina: Adding Character to Construction

 

When it comes to construction, rock has been used for thousands of years!¹

Just look around, and you’ll see modern-day examples of history in the making. From old stone walls to bridges and dams, rock structures are all around us. Something else you might notice is the variation in rock colors.

If you take a trip to arid areas — like where Natina is headquartered in Arizona — you don’t even need to be a geologist to see the varying red-to-black rocks.

But what you’re actually looking at is a coating on the rocks called desert varnish.²

 

WHAT IN THE WORLD IS DESERT VARNISH?

It’s sort of like Mother Nature’s way of doing a makeover!

But specifically, desert varnish is a natural coating that’s made up of clay minerals, manganese, and/or iron oxides and hydroxides, as well as a few other particles, such as sand grains and trace elements.

The real VIPs, aka the distinctive elements, of the varnish are manganese (Mn) and iron (Fe). They work together to give this mineral makeup its distinctive look, but that’s not all it takes.²

HOW DOES DESERT VARNISH FORM?

It’s not just the mineral makeup of the rocks that gives them the desert varnish.

Bacteria take manganese from the environment, oxidize it and cement it onto rock surfaces, along with clay and other particles. This creates a gorgeous and unique coating.

The environmental sources for desert varnish components come from outside of the rock, most likely from atmospheric dust and surface runoff. In areas where water cascades over cliffs, the rocks feature stunning streaks of black varnish.² 

So, the next time you’re admiring the beauty of desert varnish, remember that it’s all thanks to the expert skills of these amazing bacteria and a little help from Mother Nature herself.

Interestingly, it’s by looking at rocks like these that scientists have calculated the age of our planet to be approximately 4.5 billion years old.³

That’s plenty of time for desert varnish to form on rocks, but what if you need it to happen a bit quicker? We have a “solution” for that! But first, we want to cover more about patina — whether it be on rocks or metal.

 

EROSION PREVENTION CAN GET ROCKY

Patina, such as desert varnish, is often associated with time-tested structures, but it can also be a desirable finish for new construction. That’s especially true if your project needs to blend into an existing area, such as along a river bank where part of it has eroded, but the other parts haven’t. 

When erosion happens, there are a few ways crews mitigate the problem:

— AROUND ROADWAYS: Say there’s a landslide. What happens next is a cut slope is typically required for roadway placement or widening in areas that traverse a hillside. A cut slope is the vertical cut adjacent to the road, where earth is removed to accommodate the road.⁴

— AROUND WATER: When erosion occurs on shorelines, the first step is often to build retaining walls, but they offer no ecological benefits, are a barrier to wildlife and will require replacement down the road. Other approaches are re-sloping the land, adding a rock toe — a low layer of rocks along the shore — or adding irregular-shaped rocks called riprap.⁵

— FOR MULTIPLE AREAS: Geotextiles are porous fabrics used for erosion and sediment control purposes in sediment traps and basins, post-construction stormwater control measures and stone-lined stormwater conveyances — including spillways.⁶

 

When adding in structural components like these, it can be an eyesore. But it doesn’t have to be.

For instance, when building a rock toe to prevent shoreline erosion, a natural patina on the rocks can add an attractive touch, while also being environmentally friendly. 

Plus, if there are other construction elements, such as a road guardrail or handrail next to the water, Natina can add patina to that, too!

So, let’s talk about patina on various metals because often, construction projects contain multiple building materials.  

 

 

COPPER: THE METAL THAT GETS BETTER WITH AGE

Copper statues or roofs that look a little green and stand out in a good way are due to the patina that forms as copper ages gracefully (like we all want to)!

It happens because when copper is exposed to oxygen and weathering, it creates a chemical reaction that naturally encourages a blueish, greenish, brownish film. One of the most famous examples of copper experiencing patina is the Statue of Liberty.⁷

HOW TO TELL THE DIFFERENCE BETWEEN RUST, TARNISH AND PATINA

Have you ever looked at a piece of metal and wondered if its discoloration was rust, tarnish or just a natural patina like on Lady Liberty?

Restorer for O’Sullivan Antiques in New York City, Eileen Fulton, explains that patina is just a color change, and it doesn’t flake off from metals like copper. Rust, on the other hand, is red and is typically found only on iron, while tarnish is a thin layer that appears black or gray and affects many different metals, such as antique silver spoons.⁸

Now you’ll know exactly what you’re looking at when you see a piece of metal. And when it comes to rock, you’ll see similar colorations, as we’ve previously discussed.  

 

NATURE VERSUS NATINA

We’ve covered how desert varnish can take thousands of years to develop. But, who has that kind of time? Luckily, Natina’s color technology can speed up this process and recreate the natural patina of rock without harming the underlying surface. 

Our Natina Rock Solution can save the day in just a matter of weeks! That’s a far faster timeline than it takes for rocks to naturally age and develop a desert varnish. 

 

2 REASONS TO USE NATINA ON ROCK 

1. SAVE TIME (LOTS OF IT!): Speed up the natural patina process that the earth takes thousands of years to create. Natina technology can create the same effect in a matter of weeks, which can save time and money in construction projects — especially when time is of the essence.
2. BLEND ROCK & MATERIALS INTO SURROUNDINGS: Recreate natural-looking patina with our color technology. Natina can enhance the look of your rocks without damaging the surface, creating a more natural look that blends in with the surrounding environment. Plus, you can use Natina on any new construction materials, such as steel and concrete, and blend them into the rocks, too. Choosing to use existing rock and color it to the desired shade of brown reduces the need for excavation and transportation, making it a more eco-friendly option than bringing in new rocks that match the color you want. 

 

CHOOSE NATINA    

Choose Natina for your next construction project and we’ll work our magic, just like we’ve done on our previous projects! Check out our work, here. We can color rock, steel and concrete, making us your one-stop-shop for beautifying your total project.

 

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Sources

¹ Study.com

² National Park Service

³ National Geographic

⁴ WSDOT

⁵ Vermont Department of Environmental Conservation

⁶ Environmental Protection Agency

⁷ Australian Academy of Science

⁸ Martha Stewart