Sapphire single crystals

Ruby single crystals

Large single crystals of Ruby (and other crystals such as Sapphire, Garnets, etc...) grown by the Horizontal Directed Crystallization Method (dimensions 250 x 150 x 20-30 mm).


high melting point, extremely hard and resistant to abrasion, low dielectric constant - excellent electroinsulating properties, low friction coefficient, shock resistant, high refractive index, broad optical transparency (from UV to IR), chemically inert and stable


laser, jewelery, optics, optoelectronics, microelectronics, semiconductors, chemical industry, substrates, rods, ribbons, components of machinery and equipment, such as water and electrical meters, relays and watches and other applications

Ruby single crystal

Basic properties:

Physical properties:
Chemical formula Al2O3 : Cr3+
Symmetry ¯3m, R3c
a = 4.748 Å
c = 12.957 Å
Specific mass 3 984 kg.m-3 - 4 010 kg.m-3
Thermal properties:
Melting point 2 323° K
Thermal expansion 5.0 x 10-6 K-1
Maximum temperature of application 2 125 - 2 225 K
Mechanical properties:
Mohs hardness 9 - 9.4
Tensile strength 415 MPa
Compression strength 2 000 MPa
Bending strength 700 MPa
Optical properties:
Refractive index 1.765 at 0.65 µm
Transmission 0.17 - 6.5 µm
Chemical properties:
Solubility insoluble in common bases and acids under 1000° C
(is attacked only by HF and H3P04 at above 300° C)
Chemical stability stable in contact with W, Mo, SiC
(in O2 absence) up to melting point

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