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Zinc Sulfide (ZnS) Optical Material

Zinc sulfide is a non-glass, inorganic optical material. It has the highest melting temperature and a moderately high thermal conductivity among non-glass optical ceramics. The graph bars on the material properties cards below compare zinc sulfide 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

75 GPa 11 x 106 psi

Poisson's Ratio


Thermal Properties

Melting Onset (Solidus)

1830 °C 3330 °F

Specific Heat Capacity

520 J/kg-K 0.12 BTU/lb-°F

Thermal Conductivity

27 W/m-K 16 BTU/h-ft-°F

Thermal Expansion

6.5 µm/m-K

Otherwise Unclassified Properties


4.1 g/cm3 260 lb/ft3

Light Transmission Range

0.37 to 14 µm

Refractive Index


Common Calculations

Stiffness to Weight: Axial

10 points

Stiffness to Weight: Bending

34 points

Thermal Diffusivity

13 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