Sapphire

Name:
Sapphire
Detailed information:

M Formula:	(Al2O3)
Properties:
Hard, crystalline solid. D 3.98, Mohs hardness 9.0, mp 2040C, dielectric strength 480 kV/cm, dielectric constant 9.0 (20C), coefficient of friction 0.05 micron, inert to strong acids and alkalies, excellent high-temperature stability. Can be sealed to glass. High transmission in infrared and ultraviolet.
Available Forms:
Rods, spheres, disks, whiskers, single crystals.
Use:
Electron and microwave tubes, optical elements in radiation detectors, substrate for thin-film components and integrated circuits, abrasive, record needles, precision instrument bearings, aluminum composites, micromortars for hand-pulverizing chemicals.

See Corundum.