Crystallographic
Syngony	Cubic
Symmetry Class	m3m Pm3m
Lattice Constants	a = 4.567 Å

Optical
Refractive Index at n10.0	1.740
Refractive Index at n40.0	1.678
Thermal Coefficient of Refractive Index for 0-30°C	(-1.27) ... (-1.51) x 10-5
Transmission Range, microns	0.25 - 55
Absorbance m (l), cm -1
at 40 microns	0.1
at 45 microns	0.33
at 50 microns	0.5

Thermal
Thermal Linear Expansion, °C-1 for 0-30 °C	48.1 x 10-6
Thermal Conductivity, W/(m * °C) at 25 °C	1.1
Specific Heat Capacity, J/(kg * °C)	200
Melting Point, °C	621

Mechanical
Density, g/cm3	4.509
Mohs Hardness	1-2
Young Modulus (E), Pa	2 x 109
Shear Modulus (G), Pa	6.24 x 109
Poisson Ratio	0.214

Chemical
Molecular Weight	259.81
Solubility
in water, gram/100 cm3	44
in acids	soluble

Ref. Index vs. Wavelength l
Wavelength, Microns	Refractive Index
0.25	2.210
0.5	1.807
1.0	1.758
2.0	1.747
3.0	1.744
5.0	1.743
10.0	1.740
15.0	1.735
20.0	1.728
25.0	1.719
30.0	1.708
35.0	1.695
40.0	1.678
45.0	1.659
50.0	1.637
55.0	1.611

Custom sizes and specifications are available on request.