Quartz Worktops FAQ · Hardness
Is quartz harder than granite?
Honest answer: slightly yes, on the Mohs scale. Quartz scores 7 to granite’s 6-7. In real UK kitchen use the practical difference is small. Both materials handle daily wear excellently. Here is what the hardness number actually means and where it matters.
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Quartz scores 7 on the Mohs scale of mineral hardness, the universal standard for measuring scratch resistance in geology. Granite scores between 6 and 7 depending on its specific mineral composition (granites containing quartz crystals score higher, those with more feldspar and softer minerals score lower). So quartz is technically slightly harder than most granite. Diamond at the top of the scale scores 10. Talc at the bottom scores 1. Both quartz and granite sit in the upper third of the scale where everyday kitchen items cannot scratch them.
The practical difference between Mohs 7 quartz and Mohs 6.5 granite is small in real kitchen use. Both materials are harder than steel knives (Mohs 5-6), so neither will be scratched by normal cooking activity. Both handle daily wear, occasional impacts and decades of use without surface scratches developing. Where the slight hardness advantage matters more is in subtle long-term polish retention and resistance to micro-abrasion from cleaning. This page sets out what the hardness numbers actually mean, where the difference matters in real UK kitchens and the more practical durability factors that often outweigh the Mohs comparison entirely.
Both quartz and granite are harder than your knives. The Mohs comparison wins arguments online. The actual durability winners are install quality and daily care.
— Rock & Co Showroom Team
Mohs hardness in real kitchen terms
The Mohs scale is universal but its practical relevance in kitchens is less than it might seem. Five real-world hardness implications matter more than the headline number.
Both materials beat everyday kitchen items
Mohs 7 quartz and Mohs 6.5 granite both sit comfortably above the hardness of steel knives, ceramic dishes, glass and most kitchen items that might come into contact with the surface. Neither material can be scratched by normal kitchen use. The hardness comparison only becomes relevant in unusual contact scenarios with industrial materials harder than 6.5.
Where quartz’s slight hardness edge does pay off is in subtle long-term polish retention. Daily cleaning with microfibre cloths and occasional contact with hard items create micro-abrasion over years. Quartz at Mohs 7 holds its polish slightly better in heavy-use prep zones across decades. This is a real but small advantage in normal kitchens. Far more important factors include install quality, daily care habits and avoiding harsh chemicals.
Knife-resistant
Polish retention
Care more important
Both very durable
Four UK kitchen scenarios where hardness matters
Real situations where the hardness difference between quartz and granite has practical implications, plus the more common scenarios where it does not.
Daily knife use on prep zones
Hardness barely matters. Both quartz and granite are harder than steel knives. Neither will scratch from normal cutting. Use a chopping board anyway to protect your knife edge and the polished surface.
Long-term polish retention
Quartz slightly favoured. The Mohs 7 hardness holds polish marginally better in heavy-use prep zones across 15-20 years. Both materials still look good but quartz has the small edge.
Heavy item placement
Hardness barely matters. Setting a heavy mixer, food processor or KitchenAid down does not threaten either material. Impact resistance is the relevant factor here, not hardness.
Industrial cleaning equipment
Hardness can matter. Commercial cleaning equipment with abrasive components could theoretically affect granite slightly more than quartz. In domestic UK kitchens this is rarely relevant.
UK pricing where the materials compete
Three escalating tiers showing how quartz and granite compare on price across UK installations. Hardness is similar but other factors differ.
- Quartz at £280/m²
- Granite at £220/m²
- Granite slightly cheaper
- Hardness essentially equivalent
- Quartz at £420/m²
- Granite at £350/m²
- Hardness practically equivalent
- Choice based on other factors
- Premium quartz from £600/m²
- Premium granite from £500/m²
- Hardness similar
- Aesthetic and brand drive choice
The hardness difference between quartz and granite is not significant enough to drive a UK pricing premium. Other factors like maintenance and aesthetic decide most installations.
In real UK kitchens, daily care habits matter more than the hardness difference between quartz and granite. Bleach use damages both. Sensible care preserves both. Hardness wins arguments online but care wins in your kitchen.
Hardness across worktop materials
A side-by-side view of Mohs hardness and related durability factors across common UK worktop materials.
| Quartz | Granite | Marble | Laminate | |
|---|---|---|---|---|
| Mohs hardness | 7 | 6-7 | 3-4 | ~2-3 |
| Knife-scratch resistant | Yes | Yes | No | No |
| Long-term polish retention | Excellent | Excellent | Moderate | Variable |
| Impact resistance | Good | Good | Moderate | Poor edges |
| Daily wear handling | Excellent | Excellent | Sensitive | Wears in 5-10 yrs |
| Sealing for hardness preserve | None | 1-2 yrly | 6-12 monthly | None |
| Realistic durability lifespan | 15-25 yrs | 20+ yrs | 15-20 yrs | 5-10 yrs |
7 ways to preserve quartz’s hardness advantage
The hardness rating delivers real durability only if you avoid the small handful of habits that work against it.
Use chopping boards anyway
Even though quartz is harder than your knives, direct cutting can dull the polished finish over years. A chopping board protects both the slab and the knife edge.
Skip abrasive scrubbers
Steel wool, scouring pads and gritty kitchen sponges scratch the polish over time. Soft microfibre cloths handle every cleaning need without abrasion. Hardness rating does not protect against deliberate scrubbing.
Avoid harsh chemicals
Bleach and harsh cleaners gradually break down the polished surface even on hard quartz. Mild soapy water for daily and quartz-specific products for weekly preserves the surface long-term.
Mind the polish, not the hardness
The Mohs 7 hardness protects the underlying material. The polished surface is more delicate. Care routines that protect the polish (microfibre, mild cleaners) keep the slab looking new.
Lift heavy items rather than slide
Sliding heavy items like cast iron pans, food processors or stand mixers can leave faint marks even on hard surfaces. Lifting and placing rather than dragging protects the polish.
Address spills before they dry
Hardness does not prevent staining from pigmented spills if left for hours. Quick wipes within an hour prevent most marks regardless of how hard the underlying slab is.
Trust the durability rating
Mohs 7 quartz handles all normal kitchen activity without scratching. Worry less about everyday hardness threats and more about the cleaning chemistry and care routine.
How hardness translates to long-term performance
Five stages of how the hardness rating actually affects quartz performance across the typical UK lifespan.
No daily impact
Hardness rating delivers immediate scratch resistance. Daily knife and item contact creates no visible wear. Slab looks identical to install day.
Polish still showroom
Hardness has resisted thousands of contact events with everyday kitchen items. No visible scratches developed. Polish remains in showroom condition.
Subtle prep zone wear
Hardest-use prep areas may show very subtle polish dulling visible only in specific lighting. Hardness has held the underlying slab structure intact. Polish is the variable.
Mature performance
Hardness still delivers structural integrity. Polish dulling in heavy zones is now noticeable up close in some installations. Optional polish refresh restores showroom shine.
Hardness still doing work
Slab structurally sound at year 25 thanks to underlying hardness. Polish refresh option restores surface entirely. Quartz often outlasts the kitchen around it.
Three hardness misconceptions that lead to bad decisions
From years of customer conversations about hardness, these are the three most common misconceptions that lead to confused material choices.
“Harder is always better”
Not necessarily. Hardness affects scratch resistance only. Heat tolerance, hygiene, install quality and aesthetics all matter equally or more. The hardest available material may not be the best fit for a specific kitchen.
“Hardness means I can skip chopping boards”
Wrong. Even at Mohs 7, direct cutting on quartz dulls the polished surface over years. Use chopping boards regardless of hardness rating. The slab is harder than knives but the polish is more delicate.
“Hardness protects against staining”
Wrong. Hardness affects scratching, not staining. Quartz’s stain resistance comes from the non-porous structure rather than hardness. Different properties handle different threats.
Looking for more quartz worktop answers?
This article is part of our complete quartz worktops FAQ. Sixty-plus quick answers to the questions UK homeowners ask us most often, all written from the showroom floor by a team that has fitted quartz for over twenty years.
Where to go from here
For the broader head-to-head comparison that goes beyond hardness, our piece on quartz vs granite worktops covers the full set of factors that drive UK kitchen choice between these two materials.
For the related question of scratch resistance specifically, our article on is quartz scratch resistant covers exactly what the Mohs 7 hardness delivers in real UK kitchens.
And for the chip and crack durability aspect that hardness does not directly address, our piece on can quartz chip or crack covers the impact resistance side of the durability question.
For the wider context of all our material answers, the full quartz worktops FAQ covers every question we are asked across the showroom and on the phone.
Quick answers
What is the Mohs scale and why does it matter?
The Mohs scale is the universal mineral hardness rating from 1 (softest, talc) to 10 (hardest, diamond). For kitchen worktops it indicates scratch resistance. Materials above Mohs 6 are knife-scratch resistant and suitable for daily prep work.
Will quartz really resist all kitchen knives?
Yes, all standard kitchen knives. Steel knives sit at Mohs 5-6, quartz at Mohs 7. The slab is harder than the knife edge so direct cutting cannot scratch it. Use a chopping board anyway to protect the polish and knife edge.
If quartz is harder, why does anyone choose granite?
Many reasons unrelated to hardness. Granite is heat-tolerant up to 480°C vs quartz at 150°C. Granite has natural variation that some prefer aesthetically. Granite is sometimes slightly cheaper at standard tier. Hardness is one factor among many.
Does the slight hardness difference matter in practice?
Marginally yes for very long-term polish retention. Quartz at Mohs 7 holds polish slightly better than granite at Mohs 6.5 across 20+ years. In real terms the difference is small. Care routines matter more than the rating gap.
Are there harder kitchen worktop materials than quartz?
Yes, a few. Sapphire and corundum (Mohs 9) are theoretically harder but not used as worktops. Diamond at Mohs 10 obviously not. Of practical kitchen materials, quartz is at the top end with similar-hardness alternatives like Dekton and certain hard granites.
Want to compare quartz and granite samples?
Pop into our Stevenage showroom or give us a call. We hold both materials on display so you can see and feel the practical difference between them rather than just compare numbers.