Sapphire   (Al₂O₃)

Synthetic sapphire is an anisotropic crystalline material with many unique optical and physical properties which make it a material of choice for many optical applications:

• Sapphire transmits over a very broad spectrum, 150nm to 6.0µm
• Extreme surface hardness. Sapphire may only be scratched by diamond, boron nitride and of course, itself
• High mechanical strength
• Extremely high melting temperature
• Excellent electrical properties.  Low dielectric constant
• Sapphire is chemically inert and insoluble in virtually everything up to very high temperatures
• Very high thermal conductivity. Sapphire can be effectively force heated or cooled very quickly
• High refractive index.  n = 1.8337 @ 265.2nm  to n = 1.5863 @ 5577nm
• Sapphire is water clear

Main Properties