Properties |
Soda–lime glass (for containers)[2] |
Borosilicate (low expansion, similar to Pyrex, Duran) |
Glass wool (for thermal insulation) |
Special optical glass (similar to Lead crystal) |
Fused silica |
Germania glass |
Germanium selenide glass |
Chemical composition, wt% |
74 SiO2, 13 Na2O, 10.5 CaO, 1.3 Al2O3, 0.3 K2O, 0.2 SO3, 0.2 MgO, 0.01 TiO2, 0.04 Fe2O3 |
81 SiO2, 12.5 B2O3, 4 Na2O, 2.2 Al2O3, 0.02 CaO, 0.06 K2O |
63 SiO2, 16 Na2O, 8 CaO, 3.3 B2O3, 5 Al2O3, 3.5 MgO, 0.8 K2O, 0.3 Fe2O3, 0.2 SO3 |
41.2 SiO2, 34.1 PbO, 12.4 BaO, 6.3 ZnO, 3.0 K2O, 2.5 CaO, 0.35 Sb2O3, 0.2 As2O3 |
SiO2 |
GeO2 |
GeSe2 |
Viscosity log(η, Pa·s) = A + B / (T in °C - To) |
550–1450 °C: A = -2.309 B = 3922 To = 291 |
550–1450 °C: A = -2.834 B = 6668 To = 108 |
550–1400 °C: A = -2.323 B = 3232 To = 318 |
500–690 °C: A = -35.59 B = 60930 To = -741 |
1140–2320 °C: A = -7.766 B = 27913 To = -271.7 |
515–1540 °C: A = -11.044 B = 30979 To = −837 |
Glass transition temperature, Tg, °C |
573 |
536 |
551 |
~540 |
1140 |
526 ± 27[3][4][5] |
395 [6] |
Coefficient of thermal expansion, ppm/K, ~100–300 °C |
9 |
3.5 |
10 |
7 |
0.55 |
7.3 |
|
Density at 20 °C, [g/cm3], x1000 to get [kg/m3] |
2.52 |
2.235 |
2.550 |
3.86 |
2.203 |
3.65 [7] |
4.16 [6] |
Refractive index nD[8] at 20 °C |
1.518 |
1.473 |
1.531 |
1.650 |
1.459 |
1.608 |
1.7 |
Dispersion at 20 °C, 104×(nF - nC)[8] |
86.7 |
72.3 |
89.5 |
169 |
67.8 |
145 |
|
Young's modulus at 20 °C, GPa |
72 |
65 |
75 |
67 |
72 |
43.3 [9] |
|
Shear modulus at 20 °C, GPa |
29.8 |
28.2 |
|
26.8 |
31.3 |
|
|
Liquidus temperature, °C |
1040 |
1070[10] |
|
|
1715 |
1115 |
|
Heat capacity at 20 °C, J/(mol·K) |
49 |
50 |
50 |
51 |
44 |
52 |
|
Surface tension, at ~1300 °C, mJ/m2 |
315 |
370 |
290 |
|
|
|
|
Chemical durability, Hydrolytic class, after ISO 719[11] |
3 |
1 |
3 |
|
|
|
|