Crystallographic
Syngony	Hexagonal
Symmetry Class	P3221
Lattice Constants	a = 4.9138 Å c = 5.4052 Å

Optical
Refractive Index no at n0.436	1.5538
Refractive Index at ne at n0.436	1.5632
Thermal Coefficient of Refractive Index at 340 nm for +20/+100 °C
no	-5.01 x 10-6
ne	-3.93 x 10-6
Transmission Range, microns	0.15 - 3.3

Thermal
Thermal Linear Expansion, °C-1 for 0/+20 °C	13.24 x 10-6
Thermal Conductivity, W/(m * °C) at 25 °C
no	6.82
ne	11.43
Specific Heat Capacity, J/(kg * °C)	0.741 x 103
Melting Point, °C	1470

Mechanical
Density, g/cm3 at 20 °C	2.649
Mohs Hardness	7
Vickers Microhardness, Pa	981 x 107
Young Modulus (E), Pa
no	8.7 x 1010
ne	10.5 x 1010

Chemical
Molecular Weight	60.06
Solubility
in water, gram/100 cm3	insoluble

Ref. Index vs. Wavelength l
Wavelength, Microns	Refractive Index no	Refractive Index ne
0.2001	1.6493	1.6623
0.2503	1.6003	1.6114
0.3034	1.5770	1.5872
0.4047	1.5572	1.5667
0.5086	1.5482	1.5575
0.6438	1.5423	1.5513
1.0000	1.5350	1.5438
1.2000	1.5323	1.5410
1.4000	1.5297	1.5383
1.6000	1.5270	1.5355
1.8000	1.5241	1.5324
2.5000	1.5116	1.5195
3.0000	1.4996	1.5070

Custom sizes and specifications are available on request.