Quartzite COMM
Grade
COMM = commercial/micaceous quartzite
Choose the commercial micaceous stock (SiO₂ 85–95 % with feldspar and mica) for richer veining, accepting a softer, more staining-prone metamorphic sandstone that needs resin backing and sealing.
Values for the COMM condition
Other Quartzite tempers and conditions
Quartzite is listed in 2 conditions; see the grade overview at Quartzite.
- COMM
- PURE
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
COMMThis page Commercial/micaceous quartzite | Choose the commercial micaceous stock (SiO₂ 85–95 % with feldspar and mica) for richer veining, accepting a softer, more staining-prone metamorphic sandstone that needs resin backing and sealing. | — | 11 | — | — | 4 W/m·K |
PUREDefault High-purity orthoquartzite slab (SiO₂ ≥ 95 %), polished | Pick the polished high-purity orthoquartzite slab (SiO₂ ≥ 95 %) for countertops and heavy-wear floors: highest hardness and scratch resistance with low water absorption. | — | 17 | — | — | 6 W/m·K |
What is Quartzite COMM?
Quartzite COMM is Quartzite in the COMM grade — choose the commercial micaceous stock (SiO₂ 85–95 % with feldspar and mica) for richer veining, accepting a softer, more staining-prone metamorphic sandstone that needs resin backing and sealing. Quartzite COMM has a tensile strength of 11 MPa (1.6 ksi), weaker than 70% of natural material grades. The elastic modulus is 58 GPa (8.41 Msi). Quartzite COMM has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 87% of natural material grades. It melts at 1,670°C (3,038 °F). PURE is the default condition FabDigit quotes; COMM is available on request or by drawing note.
Advantages
- Conducts heat well — 4.3 W/m·K (2.48 BTU/hr·ft·°F), better than 98% of natural material grades
- Stiff — 58 GPa (8.41 Msi), better than 94% of natural material grades
- High service temperature — 400°C (752 °F), better than 94% of natural material grades
- Good corrosion resistance — 80/100, better than 84% of natural material grades
- Low embodied carbon — 0.22 kg CO₂/kg, better than 84% of natural material grades
Limitations
- Difficult to machine — 12/100, worse than 98% of natural material grades
- Heavy — 2.65 g/cm³ (0.0957 lb/in³), worse than 87% of natural material grades
Quartzite COMM properties
Typical room-temperature values for Quartzite COMM; 12 are specific to this condition. Other listed values are Quartzite reference data and may not represent this condition. Bars are the position among natural material grades.
Physical3
Quartzite COMM has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 87% of natural material grades. It melts at 1,670°C (3,038 °F).
Mechanical11
Quartzite COMM has a tensile strength of 11 MPa (1.6 ksi), weaker than 70% of natural material grades. The elastic modulus is 58 GPa (8.41 Msi).
Thermal5
Quartzite COMM is rated for continuous service to 400°C (752 °F). It conducts heat at 4.3 W/m·K (2.48 BTU/hr·ft·°F), better than 98% of natural material grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical1
Quartzite COMM has an electrical resistivity of 1,000,000 Ω·m.
Chemical & Environmental1
Corrosion resistance is very good (80/100), better than 84% of natural material grades.
Sustainability4
Producing a kilogram of Quartzite COMM takes about 3 MJ of energy and emits 0.22 kg of CO₂ — less than 84% of natural material grades. Typical recycled content is 0%.
Manufacturability2
Quartzite COMM's machinability is not recommended (12/100, worse than 98% of natural material grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Quartzite COMM
Is Quartzite easy to machine?
Process only with diamond tooling — bridge saw, waterjet or CNC router — with full water cooling and low feed rates. Free silica dust requires wet cutting plus respiratory protection.
Can Quartzite be welded?
Not weldable; seams are bonded with epoxy or unsaturated polyester stone adhesive, and backs can be mesh- or resin-reinforced.
Can Quartzite be formed, bent or molded?
No plastic forming: shape by sawing, waterjet profiling, hole cutting and edge grinding. Thin panels should be backed with aluminium honeycomb to prevent brittle fracture.
What surface finishes work on Quartzite?
Step through resin diamond pads to 3000 grit for high gloss; matte, flamed, bush-hammered and antiqued surfaces are also available. A penetrating stain-resisting sealer is recommended.
Quartzite chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SiO2quartz, partly recrystallized | 85 – 99.5 | 96 |
| Al2O3feldspar/mica/sericite | 0.2 – 6 | 1.8 |
| Fe2O3hematite/limonite; controls yellow-red hue | 0.05 – 2 | 0.5 |
| K2O+Na2O | 0.05 – 3 | 0.7 |
| CaO+MgO | 0.02 – 1.5 | 0.3 |
| TiO2 | 0.01 – 0.5 | 0.1 |
| LOI | 0.05 – 1.5 | 0.3 |
Quartzite COMM — frequently asked
What is Quartzite COMM used for?
Quartzite COMM is typically used for kitchen countertops, flooring and wall cladding, exterior paving and landscaping. In short: hardest common countertop stone; diamond tooling only; acid-resistant natural stone.
What is the tensile strength of Quartzite COMM?
Quartzite COMM has a typical tensile strength of 11 MPa (1.6 ksi) — weaker than 70% of natural material grades. Strength varies by condition: see the 2 listed tempers.
Is Quartzite COMM easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 98% of natural material grades). Process only with diamond tooling — bridge saw, waterjet or CNC router — with full water cooling and low feed rates. Free silica dust requires wet cutting plus respiratory protection.
Can Quartzite COMM be welded?
Not weldable; seams are bonded with epoxy or unsaturated polyester stone adhesive, and backs can be mesh- or resin-reinforced.
What surface finishes work on Quartzite COMM?
Step through resin diamond pads to 3000 grit for high gloss; matte, flamed, bush-hammered and antiqued surfaces are also available. A penetrating stain-resisting sealer is recommended.
Can Quartzite COMM be formed, bent or molded?
No plastic forming: shape by sawing, waterjet profiling, hole cutting and edge grinding. Thin panels should be backed with aluminium honeycomb to prevent brittle fracture.
What is the maximum service temperature of Quartzite COMM?
Quartzite COMM is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM C616 Standard Specification for Quartz-Based Dimension Stone — ASTM International (2023)
- Dimension Stone Design Manual — Natural Stone Institute (2016)
- Rock Physics & Phase Relations: A Handbook of Physical Constants — American Geophysical Union (1995)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.