Fused quartz

Fused quartz is a man made mineral, manufactured principly from sands. It is non-crystaline, and in a high purity state is a useful material for high performance fluid and gas delivery. It's mechanical and thermal properties are superior to that of glass, priciply due to the purity (or, rather, the lack of impurities). For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equiptment.

See also: quartz, list of minerals

Properties of Clear Fused Quartz

(Based on information in Fused Quartz Catalogue Q-7A, General Electric Company)

• Density: 2.203 g/cm³
• Hardness: 7 (Modified Scale); 5.3-6.5 (Mohs Scale)
• Tensile strength: 48.3 MPa
• Compressive strength: >1.1 GPa
• Bulk modulus: ~37 GPa
• Rigidity modulus: 31 GPa
• Young's modulus: 71.7 GPa
• Poisson's ratio: 0.16
• Coefficient of thermal expansion: 5.5E-7 cm/(cm*K) (average from 20°C to 320°C)
• Thermal conductivity: 1.3 W/(m×K)
• Heat capacity: 45.3 J/mol
• Softening point: ~1665°C
• Annealing point: ~1140°C
• Strain point: 1070°C
• Electrical resistivity: >10¹⁸ Ω×m
• Dielectric constant: 3.75 at 20°C 1 MHz
• Dielectric loss factor: less than 0.0004 at 20°C 1 MHz
• Index of refraction: 1.4585