Sapphire created through an process that usually involves high temperature.
Physical Properties
Crystalline Structure
Rhomboedral Hexagonal Single Crystal
Composition
AI2O3
Purity
99.99%
Cleavage
Conchoidal
Density
3.99-3.98 g/cm3
Disclosation Density
109-108/m2
Thermal Properties
Melting Point
2320K
Softening Point
2070K
Specific Heat
7.5*102 J/Kg*K at 300K
Thermal Conductivity
40W/m*K ┴ at 300K
Thermal Expansion
6.2*10-6/K// C-axis 5.4*10-6/K ┴ C-axis
Mechanical Properties
Hardness
Mohs9 Knoop 2200 face // C-axis,knoop 1800 face ┴ C-axis
Youngs Modulus
4.4*1011 pa at 300K
Modulus of Rupture
4.0*108Pa at 300K
Compressive Strength
2.1*109Pa at 300K
Tensile Strength
1.9*108Pa at 300K
Poissons constant
0.30
Chemical Properties
Acids and alkalis attack
0 to 570K
Porosity
0
Electrical Properties
Dielectric Constant
10.6 electric field // C-axis at 300K,8.6 electric field ┴ C-axis at 300K
Electrical Resistivity
109Ω*m at 770K,104Ω*m at 1270,10Ω*m at 2270K
Optical Properties
Refractive Index nD at 0.5893μm
1760 face // C-axis , 1.769 face ┴ C-axis
Dispersive Power(nF-nC)
0.011 λf=0.4861μm, λc 0.6563μm
Transmission,Disc Thickness
1 mm
-Visible Light
Excellent
-Infrared
85%0.75-5μm,70% 5.5μm,50% 6μm
-Ultraviolet
80%0.4-0.3μm,60% 0.28μm,50% 0.2μm