Crystalline (Alpha) Quartz Optical Material
Alpha quartz is a non-glass, inorganic optical material. It has a fairly high melting temperature among non-glass optical ceramics. In addition, it has a moderately low density and a moderately high heat capacity. The graph bars on the material properties cards below compare alpha quartz to other non-glass optical ceramics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
91 GPa 13 x 106 psi
Knoop Hardness
740
Poisson's Ratio
0.13
Shear Modulus
31 GPa 4.5 x 106 psi
Thermal Properties
Melting Onset (Solidus)
1590 °C 2890 °F
Specific Heat Capacity
720 J/kg-K 0.17 BTU/lb-°F
Thermal Conductivity
8.5 W/m-K 4.9 BTU/h-ft-°F
Thermal Expansion
9.5 µm/m-K
Otherwise Unclassified Properties
Density
2.7 g/cm3 170 lb/ft3
Light Transmission Range
0.13 to 3.4 µm
Refractive Index
1.6
Common Calculations
Stiffness to Weight: Axial
19 points
Stiffness to Weight: Bending
57 points
Thermal Diffusivity
4.4 mm2/s
Followup Questions
Further Reading
Handbook of Optical Materials, Marvin J. Weber, 2003
Handbook of Optical Constants of Solids, Edward D. Palik (editor), 1998