We store our engineered stone countertops on a rolling A-frame inside the warehouse. The natural stone is stacked out front in our slab yard, fenced in by ‘Fence 92037’ – a fence we built out of cedar salvaged from a La Jolla job site.
I never thought to question our stone storage practice, but stuck in traffic with David on our way to a job walk the other day, I asked, “Why do we store engineered stone inside?” What I got was a thorough primer on the environmental, functional, and aesthetic merits of natural and engineered stone.
So, what’s the difference?
Let's start by clarifying some terms. Quartz is a crystalline mineral (SiO4), but it is also a name used by some to refer to engineered stone. Why? Because engineered stone is between 80-93% mineral quartz. The rest is a combination of aggregate—sometimes recycled glass (yay!)—, resin, ethenylbenzene, pigments and other ingredients. To avoid confusion, we will be using engineered stone rather than quartz to refer to this product.
Natural stone on the other hand is just that… natural. It’s quarried from the earth (commonly) in China, Brazil, and Turkey. And then shipped to processing plants in (commonly) Italy, Spain, and Portugal to get calibrated, polished, and distributed to your local stone yards. Marble, Granite, Soapstone, Travertine, Quartzite and Limestone are popular natural stone countertop materials. Natural stones are composed of minerals such as feldspar, quartz, hornblende, hematite, garnet, calcite, muscovite.
As mentioned, engineered stone is a composite of ground natural stone (typically quartz), binders and pigments. Engineered stone can mimic intricate natural stone or it can achieve a ‘near perfect’, unblemished consistency. Engineered stones go by their brand names- Cambria, Silestone, Caesarstone, Compac, etc.
How do they compare from a functional standpoint?
STRENGTH
Winner - Tie
Both options are strong. If natural stone is a rock, engineered stone is a hard place. Stone does have natural microfissures that can be exacerbated in fabrication, transport, and installation. Engineered stone, by contrast, is usually homogenous and can take a beating. Consider stone hardness when choosing your stone to avoid purchasing something for a high traffic area that scratches or chips easily. The Mohs Hardness Scale is an elegant answer to deciding how hard a rock is. You take one rock and beat it with another, whichever breaks is softer. Do this over and over again and you get a scale with diamonds at the top (10) and talc at the bottom (1). For some perspective, Granite is a 6-7. Most engineered stones fall between 5-7.
HEAT
Winner - Natural
These days, engineered stone resists heat well-ish. The binders have been cured to resist higher temperatures than their predecessors, but the resin and colorants in engineered stone can still burn or crack. Do not put hot things directly on an engineered countertop. A simple trivet will solve this problem. The same holds for soft, light colored natural stone which are susceptible to discoloration. No need to worry about darker, harder natural stones in this department.
DISCOLORATION
Winner - Engineered*
Etching lightens a stone; staining darkens it. Some stones will etch when exposed to acids like vinegar and citrus oils. Calcareous stones such as marble, onyx, travertine and limestones are some such stones. Siliceous stones like granite, quartzite, and sandstone are less susceptible. Engineered shouldn’t really etch, but some chemicals can damage the resins and pigments in it.
The difference in this category really comes into focus when you want a particular color. That color is WHITE. When comparing a white natural stone (e.g. marble) to a white engineered stone (e.g. Caeserstone Vivid White), Vivid White is harder and less porous and thus resists staining and etching better. White natural stones are hard to find and are usually soft. If you are looking for a white countertop and you need it to stand up to some wear and tear, then go with engineered.
TEXTURE
Winner - Tie
A leather or honed finish will by definition provide more groves for contaminants to gather. A polished stone, whether engineered or natural will resist discoloration and blemishing better than a honed or leather finish. But, as Juliann likes to point out, some imperfections aren't scars, they are beauty marks. However, if you'd like to avoid those too, see our Stone Maintenance Guide for how to properly care for your countertops.
Which is more expensive? They’re comparable.
Natural stones range in price from $800 to $7000. As a general rule, marbles are more expensive than granites: they’re more expensive out of the box and they’re more expensive to maintain. A fancy marble will be marginally more expensive than a fancy engineered marble. But engineered stone is the kind of product where you get what you pay for. More expensive stones will be harder, stronger, and less fussy, and they’ll typically have better VOC and environmental regulation compliance than cheaper stones. The cheaper stones will have a lower mineral content (i.e. more filler and less solid stone chips) and are thus more prone to thermal shock.
Honestly, the more economical choice is buying secondhand—be it natural or engineered. It may take a bit more time and creativity when shopping for the stone and fabricating it, but secondhand is really the only way to get a $6,000 slab of Blue Bahia for $900. See what kind of secondhand stone we stock here.
And what about the environmental impact?
Buy secondhand. If not, keep reading.
For natural stone, the quarrying process is intense (although, not nearly as intense as mining for say, coal or diamonds) and the stone travels long distances. But, once it’s extracted, it doesn’t really need a lot of work. It’s used as-is. And while it’s not a renewable resource, it can be reused again and again. Also, there’s not a huge waste factor. Extraction and fabrication debris are often used in engineered stone, construction aggregates, and additives.
Some engineered stone are made from byproducts and recycled material content, and some, like the white "quartz," are intentionally quarried for production. It’ll take some digging (pun intended) on each manufacturer to find out how much of their engineered stone is actual byproduct and how much is intentionally quarried. What’s problematic are the resin binders being use to hold it all together. Almost everyone is using petroleum-based resins which are beasts to produce and can continue off-gassing into your home for years unless they’re complying with the highest VOC standards. There are companies experimenting with plant-based binders and recycled content material. Compac runs an essentially carbon-neutral facility out of Spain and uses a corn-based bioresin in some of their engineered surfaces.
As far as embodied energy goes, natural stone is an energy sink in terms of raw extraction, transport and hard manual labor. But engineered stone is still engineered; we have to consider the energy input for the individual components (resins, stone powders and pigments) along with the manufacture and transport of the product itself.
Until we have better data on the embodied energy in engineered stone, choosing a more sustainable stone comes down to factors specific to your project: 1. How local are the quarries, processing plants, and stone yards in relation to your home; 2. How compliant is each facility; 3. What is the stone’s longevity if it meets, or fails to meet, your design, lifestyle and budget?
What really makes the difference is buying secondhand stone. It doesn’t matter is if is engineered or natural, secondhand stone has almost no embodied energy costs. It is material diverted from landfill and made available for resale. And when you buy secondhand, you save on the energy costs that would otherwise go into procuring stone and manufacturing it anew.
What are the cons? Some stones have microfissures that are exacerbated by improper handling. The more you transport, cut and move stone, the more likely you are to exacerbate microfissures. And if something goes terribly wrong, you can’t just call up the slab yard for a replacement.
The answer? Source secondhand stone from people you trust. Here at ReFind Kitchens, our deconstruction crew is trained to remove and transport stone to minimize cracking.
*Oh yeah… why do we store engineered stone inside?
A: The resins in engineered stone can become UV compromised. You can certainly install them in sunny rooms, but we don’t recommend using them outdoors unless under a shade structure.
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What do you do with the existing fixtures that are not at the end of their useful lives? Donate them!
By donating you’ll also be saving on demo costs, you’ll be helping out the planet, and you could potentially save thousands on your taxes!
