Crystal properties
Crystal Type:	cubic, diamond structure
Transmission Range	1.8 ... 23 µm
Refractive Index	4.0034 @ 9.72 µm, 4.0028 @ 10.6 µm
Reflective Loss	52.9 % @ 10 µm
Density	5.323 g/cm3
Melting Point	956, 959, 942, 938 °C
Molecular Weight	72.59
Thermal Conductivity	58.61 W/(m K)
Specific Heat	310 J/(kg K) @ 25 °C
Thermal Expansion	5.5×10–6 / K, 6.1×10–6 / K
Hardness (Knoop)	780
Young’s Modulus	102.7 <100>, 155.3 <111> GPa
Shear Modulus	67 <100> GPa
Bulk Modulus	77.2 GPa
Rupture Modulus	93 MPa
Elastic Coefficient:	C11 = 129 / C12 = 48.3 / C44 = 67.1 GPa
Dielectric Constant	16.6 @ f = 9.37 GHz
Solubility in Water	Insoluble
Application	Electronics lenses, band pass filters, thermography
Remarks	laser damage threshold: 2.9 ...3.3 GW / cm2
Germanium substrates
List of optical crystals