What is quartzite, and how is it different from quartz and marble?
Last updated November 2026.
Quick answer
- Rock type
- Metamorphic; recrystallized quartz sandstone
- Quartz content
- At least 80% by volume; pure types near 99% SiO2
- Mohs hardness
- About 7 (one guide says 7–8); marble is 3–4
- Acid reaction
- True quartzite should not etch
- Published slab price
- $70–$200+ per sq ft installed (SlabWise, 2026)
- Sealing
- Porous to a degree; test with water, reseal when it soaks in
Quartzite is a hard, non-foliated metamorphic rock made when quartz sandstone is recrystallized by heat and pressure. It is natural stone, unlike engineered quartz, which is crushed stone in resin. It rates about 7 on the Mohs scale and should not etch, though some slabs sold as quartzite are marble or dolomite.
Ask about a piece in Quartzite
What is quartzite?
Quartzite is a hard, non-foliated metamorphic rock that began as quartz sandstone. Regional metamorphism, driven by heat and pressure in mountain-building zones, recrystallizes the sand grains and the cement between them so they interlock. The original sedimentary texture is erased, and the rock breaks through its grains rather than around them.
The British Geological Survey sets the bar at 80% quartz by volume. Very pure types run close to 99% silica, which is why most quartzite is white to gray, with pink and red from hematite and yellow, green, blue and orange from other minerals. A rock that is sedimentary but so tightly cemented that it breaks across grains is called orthoquartzite, while metaquartzite is the metamorphic type.
What are the properties of Quartzite?
| Property | Quartzite |
|---|---|
| Rock type | Hard, non-foliated metamorphic rock; a metasandstone formed by tectonic compression [1] |
| Quartz content | British Geological Survey requires at least 80% quartz by volume; pure orthoquartzite is often about 99% SiO2 [1] |
| Fracture | Grains interlock, so the rock breaks through the grains with an irregular or conchoidal fracture [1] |
| Mohs hardness | About 7, versus 6–6.5 for granite and about 3–4 for marble [3] |
| Heat | Handles a hot pan; engineered quartz resin degrades above about 300°F [3] |
| Porosity and sealing | Dense stone with a fluoropolymer sealer may need resealing every 2–3 years, porous types yearly; reseal when water soaks in within 5 minutes [3] |
| Acid reaction | Quartz-dominant rock should not etch; marble and dolomite will [3] |
| Dolomite warning | Some slabs sold as 'Super White' are dolomite marble; verify with an acid test [2] |
| Published price | $70–$200+ per sq ft installed (2026 retail guide) [2] |
Numbers in brackets refer to the sources at the end of this page. Natural stone varies block to block.
Planning a piece in Quartzite?
Tell us about the room. We reply within one business day with options, and every quote gives the exact dimensions and weight of the piece.
Is quartzite the same as quartz?
No. The names share nine letters and little else. Quartzite is natural rock, quarried and cut into slabs. Engineered quartz is roughly 90–95% ground quartz bound with 5–10% polymer resin and pigment, pressed and cured in a factory.
The practical differences follow from that. Quartzite takes heat, UV and a hot pan; resin in engineered quartz degrades above about 300°F and can fade in sunlight. Engineered quartz is non-porous and never needs sealer, while quartzite does. Quartzite is quarried in places such as the Baraboo Range in Wisconsin, the Wasatch Range in Utah and Norway, and Brazil is mined for kitchen countertops.
| Trait | Quartzite (natural) | Engineered quartz |
|---|---|---|
| Made of | Recrystallized sandstone | 90–95% quartz plus resin |
| Mohs hardness | About 7 | About 7 for the aggregate |
| Heat | Withstands hot pans | Resin damaged above about 300°F |
| Sealing | Needed | Not needed |
| Published price | $60–$200+ per sq ft installed | $50–$150 per sq ft installed |
Price ranges are retail estimates from SlabWise guides, 2026, and overlap between pages; they are not Pietra Fonte prices.
How do you test whether a slab is true quartzite?
Ask for an offcut and run two tests. A steel knife blade is Mohs 5.5–6.5, so it should not scratch quartzite but will mark marble. Then put lemon juice or vinegar on it for a few minutes: true quartzite should not etch, while marble and dolomite will dull. A retail guide notes that some slabs sold as Super White are dolomite marble.
The tests are indicative, not proof, so also ask for the quarry name and a test report. The Natural Stone Institute has issued guidance, as a retail guide relays it, telling buyers to ask for documentation on any slab sold as quartzite. 'Quartzite' is also a trade label, and the marble entry in Wikipedia notes that the stone trade uses stone names more broadly than geologists do.
How hard is quartzite, and what does that mean in a bathroom?
Quartzite typically rates about 7 on the Mohs scale, against 6–6.5 for granite and 3–4 for marble. On a vanity top that means resistance to razor, ring and tool scratches, and to the acidic splashes from cleaners and cosmetics that dull marble.
Hard does not mean unbreakable. Edges can chip when struck, and thicker slabs (3 cm rather than 2 cm) reduce that risk. On floors, polished faces get slippery when wet, so ask for a honed or leathered finish and a wet slip rating. On shower walls it needs sealing and a waterproof layer behind it; check with a licensed installer and local code.
Does quartzite work for a bathroom vanity and shower?
Yes for a vanity top, where hardness and acid resistance are an advantage, and for shower walls when sealed and waterproofed. Basins are usually a separate fixture fitted into the top, so the stone's job is the slab, not the bowl.
Sealing frequency is a judgment call. A guide quotes the old Marble Institute test, now the Natural Stone Institute's: water that soaks in within 5 minutes means it is time to reseal. Dense stone with a fluoropolymer sealer may last 2–3 years, and porous types need it yearly.
What is quartzite often mistaken for?
Soft-veined white quartzites are sold as alternatives to Carrara and Calacatta marble, and the veining does read as marble. The differences are chemical and mechanical: marble etches and scratches, quartzite does not. See Carrara, Calacatta and the broader marble page for what etching looks like.
Granite is the other neighbor, also hard, but with a speckled, grain-by-grain look where quartzite tends to show flowing, marble-like veins. Ask the supplier which one is on the slab tag.
Does Pietra Fonte make pieces in quartzite?
We don't currently offer quartzite. We carve marble, travertine, onyx and a small range of other stones to order. See the stone library for what we work in, or talk to us about a one-off piece through bespoke.
Sources
Every piece is made to order. Tell us about the room and we reply within one business day.
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