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Onyx vs Quartzite

Natural Material · grade comparison

Onyx and Quartzite are both natural material grades. Quartzite is the stronger of the two: tensile strength 17 MPa (2.47 ksi) against 6 MPa (0.87 ksi) for Onyx, about 183% more. Quartzite is stiffer (75 GPa vs 50 GPa) and Quartzite runs hotter in service (400°C vs 100°C continuous). On the shop floor, Onyx machines more easily (good vs not recommended).

OnyxChoose it when the part is machined in volume.

QuartziteChoose it when strength drives the design, or when the part sees heat.

Onyx vs Quartzite: properties

OnyxQuartzite

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

50 GPa7.3 Msi
75 GPa10.9 Msi

Shear Modulus

20 GPa2.9 Msi
29 GPa4.2 Msi

Poisson's Ratio

0.26
0.17

Tensile Strength (Ultimate)

6 MPa0.87 ksi
17 MPa2.5 ksi

Compressive Strength

90 MPa13.1 ksi
250 MPa36.3 ksi

Flexural Strength

10 MPa1.5 ksi
28 MPa4.1 ksi

Shear Strength

10 MPa1.5 ksi
34 MPa4.9 ksi

Fracture Toughness (K_IC)

0.6 MPa·√m0.55 ksi·√in
1.1 MPa·√m1 ksi·√in

Hardness, Knoop

120 HK
770 HK

Hardness, Mohs

3.5
7

Same in both: Bulk Modulus 40 GPa5.8 Msi

Physical

Density and transition temperatures.

Density

2.7 g/cm³0.1 lb/in³
2.65 g/cm³0.1 lb/in³

Porosity

1.2%
0.4%

Melting Point (Solidus)

—
1,670°C3,038 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

2.3 W/m·K1.3 BTU/hr·ft·°F
6 W/m·K3.5 BTU/hr·ft·°F

Specific Heat Capacity

850 J/kg·K0.2 BTU/lb·°F
780 J/kg·K0.19 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

8 µm/m·K4.4 µin/in·°F
11 µm/m·K6.1 µin/in·°F

Max Service Temperature (continuous)

100°C212 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 1,000,000 Ω·m3.94×10¹³ µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

22 / 100
93 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

65 / 100
7 / 100

Same in both: Polishability 88 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

12 L/kg1.4 gal/lb
25 L/kg3 gal/lb

Same in both: Embodied Energy (primary production) 3 MJ/kg1,290 BTU/lb · Embodied Carbon (primary production) 0.22 kg CO₂/kg · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

2 kN·m/kg
6 kN·m/kg

Specific Stiffness (E / density)

18.5 MN·m/kg
28.3 MN·m/kg

Thermal Diffusivity

1 mm²/s
2.9 mm²/s

Same in both: Thermal Shock Resistance Index 0

Strength versus weight

Yield strength against density for every natural material grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

Manufacturing and finishing

CapabilityOnyxQuartzite
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

Onyx vs Quartzite — frequently asked

Is Quartzite stronger than Onyx?

Yes. Quartzite has a typical tensile strength of 17 MPa (2.47 ksi) against 6 MPa (0.87 ksi) for Onyx — about 183% more.

Which is cheaper, Onyx or Quartzite?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, Onyx or Quartzite?

Onyx. Its machinability rates good (65/100) against not recommended (7/100) for Quartzite.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Onyx and Quartzite side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.