Table of Optical Crystal Characteristics 1

Material name	Lithium Fluoride (LiF)	Magnesium Fluoride (MgF₂)	Calcium Fluoride (CaF₂)	Barium Fluoride (BaF₂)	Quartz (SiO₂)
Transmission range ()	0.119.0	0.117.5	0.1312.0	0.1515.0	0.154.5
Crystal system	Cubic	Tetragonal	Cubic	Cubic	Hexagonal
Crystal structure	Rock salt	Tin oxide	Fluorite	Fluorite	-Cristobalite
Cleavage plane	100	Parallel to A to C axis	111	111	None
Color	Colorless	Colorless	Colorless	Colorless	Colorless
Density	2.639(25)	3.155(18)	3.179(25)	4.83(20)	2.648(25)
Melting point()	870	1255	1360	1280	1470
Reflection loss (for 2 surfaces)	4.4%(4)	4.8%(Visible)	5.6%(4)	6.0%(4)	8.2%(2)
Solubility index (number of grams for 100g of water)	18 0.27	18 0.0076	0 1.31X10^-3 20 1.51X10^-3 40 1.67X10^-3	0 0.159 30 0.162	Insoluble
Hardness (Knoop Number)	102113	415	158.3<110> 158.3<100>	82.0	741.0
Thermal conductivity (cal/cm sec)	2.7X10^{^-2} (41)	5.17X10^-2 (Parallel to C axis) 8.03X10^-2 (Vertical to C axis)	2.32X10^-2 (36)	2.8X10^-2 (13)	2.55X10^-2 (Parallel to C axis) 1.48X10^-2 (Vertical to C axis)
Specific heat (cal/g)	0.373(10)	0.270	0.204(0)		0.188 (12100)
Thermal expansion (/)	37X10^-6 (0100)	12.8X10^-6 (Parallel to C axis) 18.9X10^-6 (Vertical to C axis)	24X10^-6 (2060)	18.4X10^-6 (0300)	7.97X10^-6 (Parallel to C axis) 13.37X10^-6 (Vertical to C axis)
Max.diameterXheight(mm)	150X100	250X100	250X100	200X100

Material name	Fused Silica (SiO₂)	Sapphire (Al₂O₃)	Sodium Chloride (NaCl)	Potassium Chloride (KCl)	Potassium Bromide (KBr)
Transmission range ()	0.24.5	0.176.5	0.2126.0	0.2130.0	0.2340.0
Crystal system	Amorphous	Hexagonal	Cubic	Cubic	Cubic
Crystal structure		Corundum	Rock salt	Rock salt	Rock salt
Cleavage plane	None	None	100	100	100
Color	Colorless	Colorless	Colorless	Colorless	Colorless
Density	2.203	3.98	2.164(20)	1.9865(28)	2.75(23)
Melting point()	1730(softening point)	2030	801	776	730
Reflection loss (for 2 surfaces)	6.3%(2)	12.0%(4)	7.5%(10)	6.8%(10)	8.4%(10)
Solubility index (number of grams for 100g of water)	Insoluble	Insoluble	0 35.6 20 35.8 50 37.0 100 39.1	0 28.5 20 34.7 60 45.6 100 56.7	0 53.5 20 65.2 50 80.2 100 104.0
Hardness (Knoop Number)	590620	1370	15.2<110> 18.2<100>	7.2<110> 9.3<100>	5.9<110> 7.0<100>
Thermal conductivity (cal/cm sec)	2.82X10^-3 (41)	6.0X10^-2 (Parallel to C axis) 5.5X10^-2 (Vertical to C axis)	1.55X10^-2 (16)	1.56X10^-2 (42)	1.15X10^-2 (46)
Specific heat (cal/g)	0.22	0.18(25)	0.204(10)	0.162(0)	0.104(0)
Thermal expansion (/)	0.5X10^-6 (20900)	6.7X10^-6 (Parallel to C axis) 5.0X10^-6 (Vertical to C axis)	44X10^-6 (-50200)	36X10^-6 (2060)	43X10^-6 (2060)
Max.diameterXheight (mm)	250X100	60X100	160X100	160X100	160X100