{"id":3630,"date":"2026-10-15T12:48:32","date_gmt":"2026-10-15T04:48:32","guid":{"rendered":"http:\/\/www.buhotique.com\/blog\/?p=3630"},"modified":"2026-10-15T12:48:32","modified_gmt":"2026-10-15T04:48:32","slug":"what-is-the-hardness-of-quartz-4e42-0e501a","status":"publish","type":"post","link":"http:\/\/www.buhotique.com\/blog\/2026\/10\/15\/what-is-the-hardness-of-quartz-4e42-0e501a\/","title":{"rendered":"What is the hardness of Quartz?"},"content":{"rendered":"

Hey everyone, and welcome to my little corner of the web\u2014where I get to talk about the stuff I\u2019ve been obsessing over for the last decade as a Quartz supplier. If you\u2019ve ever picked up a countertop, a watch face, or even that random rock you found on a hike and thought, \u201cWait, why is this so tough?\u201d then you\u2019re in the right spot. Today we\u2019re diving into something I get asked literally every single week: what is<\/em> the hardness of quartz anyway? And for the record, this isn\u2019t just some random rock fact\u2014it matters so much when you\u2019re picking quartz for your project, whether it\u2019s a kitchen redo or a custom tile job. Quartz<\/a><\/p>\n

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First off, let\u2019s cut through the noise. I know a lot of people have heard of the Mohs scale, right? That 1-to-10 scratch test thing? Yeah, that\u2019s the main one we use for minerals, and quartz sits dead at a 7 on Mohs Hardness Scale. But wait\u2014don\u2019t just take that number at face value. Let\u2019s break this down like I\u2019m explaining it to a customer who called me panicking because a can opener scratched their old quartz countertop. Because that\u2019s basically my daily life.<\/p>\n

Here\u2019s how the Mohs scale works, super simple: it\u2019s a relative scale, not absolute. So a 7 is harder than a 6 (which is feldspar, common in granite), softer than an 8 (topaz), way softer than a 9 (corundum, like rubies and sapphires), and way softer than a 10 (diamond). But the big mistake people make is thinking that a 7 means \u201cunscratchable.\u201d Nope. The Mohs scale is just about which minerals can scratch which others. So if you take a piece of quartz (7) and rub it against another 7, they\u2019ll both scratch each other a little. If you rub quartz against something softer than 7\u2014like calcite (3) or even your kitchen knife steel (which is around 5.5), that thing will scratch the quartz, not the other way around. That\u2019s the whole point. And for what it\u2019s worth, when I hear someone say \u201cmy quartz got scratched by a knife,\u201d I don\u2019t panic\u2014most steels are only 5-5.5, so that makes total sense. We always tell customers not to cut directly on quartz, even though it\u2019s 7, because even hard stuff can show marks if you\u2019re reckless.<\/p>\n

But wait\u2014hardness isn\u2019t just scratch resistance, right? As a quartz supplier, I see a lot of customers mix up hardness with durability, and that\u2019s a huge misconception. Hardness is about how well a material resists scratching. Durability is a whole other bag\u2014it\u2019s about impact resistance, heat resistance, stain resistance, all that good stuff. For example, quartz is a super dense, non-porous material we make in our facility by mixing ground quartz (the mineral, 90-93% of the slab) with resin, pigments, and other binders. So that resin part? It\u2019s softer than quartz, right? Resin is around 2-3 on Mohs, so the only reason the whole slab is a 7 is because of all that embedded quartz crystal. But that resin is what gives quartz its flexibility, so a drop of a heavy pan (like a cast iron skillet) is way less likely to chip than, say, natural granite, which is softer but more brittle. That\u2019s the tradeoff we walk through with every client. I once had a architect client come in insisting their project needed \u201cthe hardest quartz ever\u201d and we had to explain that a 7 is actually one of the hardest common countertop materials\u2014harder than granite (which is 6-7, depending on the feldspar content), harder than most marble (3-5), way harder than solid surface materials like Corian (which is like 2-3). So when someone says \u201chard,\u201d quartz is top of the line for most everyday uses.<\/p>\n

Another question I get all the time: does quartz hardness vary between different brands? Ugh, yes and no. Let\u2019s be real\u2014not all quartz is made equal. At our facility, we use high-purity natural quartz crystals, ground to a specific particle size, mixed with UV-stabilized resin (so it doesn\u2019t yellow) and no fillers that would lower the hardness. Some cheaper brands? They add more resin, more fillers, use lower quality quartz, and their slabs end up around 6.5 on Mohs. That\u2019s a small difference, but it adds up. If you\u2019re installing quartz in a commercial kitchen where they\u2019re dragging heavy pots around and using metal utensils, a 6.5 slab will scratch way faster than a 7. I\u2019ve had customers come to us after installing a cheap quartz from a big box store a year ago, and now it\u2019s covered in scratches\u2014they thought all quartz was the same hardness, which is so not true. So when we\u2019re chatting about a project, I always pull out a little scratch test kit I keep in my truck (don\u2019t judge) to show them: I take a piece of our 7 hardness quartz, a cheap competitor\u2019s slab, and a piece of feldspar (Mohs 6). I rub them all on each other\u2014our quartz scratches the feldspar, the cheap competitor\u2019s scratches too, but the competitor\u2019s slab gets scratched by the feldspar. That\u2019s worth its weight in gold for customers who can\u2019t tell the difference between a good slab and a cheap one just by looking at it.<\/p>\n

Also, let\u2019s talk about real-world testing, not just lab numbers. I\u2019ve been in the industry for 12 years, so I\u2019ve seen thousands of quartz slabs get put through their paces. We installed a big commercial kitchen at a coffee chain in downtown Chicago two years ago, and those countertops get hit with everything: dropped metal espresso machines, sharp barista tools, acid from coffee and citrus, hot steam. A year later, we went back to inspect\u2014only a tiny, almost unnoticeable scratch in one spot where a barista dropped a 10-pound metal milk frother. That\u2019s the hardness at work. Compare that to the marble they used in a caf\u00e9 down the street\u2014last year they had to refinish all the countertops because of scratch marks from sugar shakers and knife cuts. It\u2019s not that marble is bad, it\u2019s just way softer.<\/p>\n

Wait, but what about myths? I hear so many people say \u201cquartz is harder than steel\u201d or \u201cit\u2019s almost as hard as diamond.\u201d No, that\u2019s not true. Diamond is 10, quartz is 7. Big gap. Steel is usually around 5-5.5, so quartz is harder than most steel, which is why you can\u2019t scratch quartz with a knife if you do it light. But if you press hard, or drag a knife back and forth, you will get a mark. That\u2019s not a flaw in the quartz, that\u2019s basic physics. I always use the example of a diamond: you can scratch glass with a diamond, but if you drop a diamond on concrete, it\u2019ll chip or even crack. Hardness isn\u2019t everything. Same with quartz\u2014its hardness makes it scratch-resistant, but the resin binder makes it flexible, so it doesn\u2019t crack if you drop a pan, unlike glass (which is like 5.5, harder than some steels but super brittle).<\/p>\n

Another thing I love talking about as a supplier: how quartz\u2019s hardness makes it perfect for all kinds of projects, not just kitchens. We make quartz tiles for bathroom showers, and those get scrubbed with harsh cleaning products, brushes, even pumice stones sometimes. A 7 hardness quartz will hold up way better than a porcelain tile (which is around 6-7, but more porous if it\u2019s not glazed) or natural stone (which is softer). We\u2019ve had a hotel client use our quartz for their lobby floor, and after three years of foot traffic, roller bags, and furniture moving, there\u2019s barely a scratch. That\u2019s the hardness doing its job.<\/p>\n

Now, let\u2019s get to the part that actually matters: why does this matter for you? If you\u2019re a homeowner picking quartz for your kitchen, you don\u2019t need a PhD in mineralogy. But knowing that quartz is a 7 on Mohs, that that\u2019s harder than granite, marble, and most solid surface, and that higher quality quartz is closer to a true 7 will help you make a better choice. If you\u2019re a contractor, that knowledge will help you recommend the right product for the job\u2014like, don\u2019t suggest a low-hardness quartz for a commercial space, because it\u2019ll wear out fast. If you\u2019re just a curious person (hi, that\u2019s most of my customers), now you have a fun fact to drop at your next dinner party: quartz is 7 on the Mohs scale, harder than a knife, softer than a topaz.<\/p>\n

I should also mention that even with all that hardness, quartz isn\u2019t indestructible. You can still scratch it if you drag a diamond-tipped drill bit across it (duh, that\u2019s how they cut quartz for countertops) or if you slide a piece of metal with sharp, hard edges across it with a lot of pressure. We always tell customers to use cutting boards, trivets for hot pans, and wipe up spills\u2014common sense stuff that protects any countertop, even the hardest one. Hardness doesn\u2019t mean \u201cinvincible.\u201d It just means it\u2019s way more resistant to scratches than most other materials you\u2019d use for surfaces.<\/p>\n

As someone who\u2019s in the thick of this every day, I\u2019ve seen the confusion around quartz hardness so much. New customers come in, look at samples, and ask \u201cwhy is this one more expensive than that other one?\u201d A big part of that is the quality of the quartz crystals. We source our quartz from mines in the US and Brazil that produce high-purity, consistent crystals, so our slabs have that true 7 hardness. A lot of budget brands use lower-grade quartz, more resin, and their slabs are softer, so they have to charge less, but they don\u2019t last as long. We\u2019ve had customers switch to our product after going through two sets of cheap quartz in five years\u2014they say it\u2019s worth every penny because it doesn\u2019t scratch, it doesn\u2019t yellow, and it looks good for decades.<\/p>\n

So to wrap this up: the hardness of quartz is 7 on the Mohs Hardness Scale. That number is relative, not absolute, meaning it\u2019s harder than most common minerals and surface materials, but not unscratchable. The hardness comes from the natural quartz crystals in the slab, mixed with resin binders that give quartz its durability and flexibility. Not all quartz is the same\u2014higher quality slabs will hit that true 7, while cheaper ones can dip to 6.5 or lower, which affects how well they hold up to daily use. And most importantly, that 7 hardness makes quartz one of the best all-around surface materials for kitchens, bathrooms, floors, and more, balancing scratch resistance with durability.<\/p>\n

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If you\u2019re thinking about quartz for your next project\u2014whether it\u2019s a small bathroom remodel, a big commercial build, or something in between\u2014I\u2019d love to chat. I\u2019ve been doing this long enough to help you pick the right slab, explain all the technical stuff in plain English, and make sure you get exactly what you need. Don\u2019t hesitate to reach out and start the conversation. I\u2019m here to help, not just sell quartz.<\/p>\n

Brown Marble<\/a> References:<\/p>\n

    \n
  1. Nesse, W. D. (2013). Introduction to Mineralogy. Oxford University Press.<\/li>\n
  2. Mohs, F. (1822). Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien. Leopold Sommer.<\/li>\n
  3. Quartz Manufacturers Association. (2021). Global Quartz Surface Industry Report.<\/li>\n
  4. Klein, C., & Dutrow, B. (2020). Manual of Mineral Science (23rd ed.). Wiley.<\/li>\n<\/ol>\n
    \n

    Xiamen Yigong Import and Export Co., Ltd.<\/a>
    As one of the most professional quartz suppliers in China, we also support customized service. With abundant experience, we warmly welcome you to buy high quality quartz for sale here from our factory. For price consultation, contact us.
    Address: No.850-2 Xingxi Road, Houxi Town, Jimei District, Xiamen
    E-mail: ella@xmyigong.com
    WebSite:     https:\/\/www.yigongstone.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

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