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Crystal Quartz SiO2
Optically, Crystalline Quartz is used extensively as a wave retardation medium. The birefringent properties of Quartz are of use in quarter-wave plates and in polarisers. Quartz should not be processed or used at temperatures greater than 490 °C
Crystalline quartz is also used for electronic filters and resonators. However, Crystran Ltd. does not deal in material for this application.
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| Transmission Range | 0.18 to 3.5 μm and 40μm to 100μm |
| Refractive Index | No 1.54421 ; Ne 1.55333 @ 0.6μm |
| Reflection Loss | 8.8% at 0.6 μm (2 surfaces) |
| Absorption Coefficient | n/a |
| Reststrahlen Peak | n/a |
| dn/dT | -5.5 x 10-6/°K (para) & -6.5 x 10-6/°K (perp) @ 633nm (3) (4) |
| dn/dμ = 0 | 1.3 μm |
| Density | 2.649 g/cc |
| Melting Point | 1710°C |
| Thermal Conductivity | 10.7 (para) 6.2 (perp) W m-1 K-1 at 323 K |
| Thermal Expansion | 7.1 (para) 13.2 (perp) x 10-6/°C |
| Hardness | Knoop 741 with 500g indenter |
| Specific Heat Capacity | 710 J Kg-1 K-1 (3) |
| Dielectric Constant | 4.34 (para) 4.27 (perp) at 30MHz |
| Youngs Modulus (E) | 97.2 (para) 76.5 (perp) GPa |
| Shear Modulus (G) | 31.14 GPa |
| Bulk Modulus (K) | 36.4 GPa |
| Elastic Coefficients | C11=87 C12=7 C44=58 C13=13 C14=(-)18 C33=106 (1) (2) |
| Apparent Elastic Limit | 41 MPa (5950psi) (4) |
| Poisson Ratio | n/a |
| Solubility | Insoluble in water |
| Molecular Weight | 60.06 |
| Class/Structure | Trigonal (hex) P3(2)21 (RH) and P3(1)21 (LH) |
| μm | No | Ne |
|---|---|---|
| 0.193 | 1.661 | 1.675 |
| 0.213 | 1.662 | 1.674 |
| 0.222 | 1.662 | 1.634 |
| 0.229 | 1.669 | 1.630 |
| 0.248 | 1.660 | 1.620 |
| 0.266 | 1.659 | 1.607 |
| 0.280 | 1.658 | 1.596 |
| 0.308 | 1.576 | 1.586 |
| 0.325 | 1.571 | 1.581 |
| 0.351 | 1.565 | 1.575 |
| 0.400 | 1.558 | 1.567 |
| 0.436 | 1.552 | 1.561 |
| 0.488 | 1.550 | 1.559 |
| 0.515 | 1.548 | 1.558 |
| 0.532 | 1.547 | 1.556 |
| 0.59 | 1.544 | 1.553 |
| 0.633 | 1.543 | 1.552 |
| 0.670 | 1.542 | 1.551 |
| 0.694 | 1.541 | 1.550 |
| 0.755 | 1.539 | 1.548 |
| 0.780 | 1.539 | 1.548 |
| 0.820 | 1.538 | 1.547 |
| 0.980 | 1.537 | 1.546 |
| 1.064 | 1.534 | 1.543 |
| 1.3 | 1.531 | 1.539 |
| 1.55 | 1.528 | 1.536 |
| 2.01 | 1.521 | 1.529 |
Quartz is mined naturally, but more commonly produced synthetically in large, long-faceted crystals. Quartz is positive birefringent. Be careful not to confuse terminology in this material, as “Fused Quartz” is often used to denote the glassy non-crystalline form better known as Silica.
Normal Quartz is Alpha Quartz and normally RH rotating. LH rotating is available on special order. See our guide on distinguishing the types.
At temperatures >490°C, Crystal Quartz starts to revert to glassy state, a process which is complete by 530°C. At this time, as annealling is unlikely, fracture of component is probable.
REFERENCES:
(1)J.V.Atansoff and P.J.Hart, Phys. Rev. Vol.59, pp 85-96 1941
(2)A.W.Lawson, Phys. Rev. Vol 59, pp.838-839, 1941
(3) F.J.Micheli, Ann.Physik 4:7 (1902)
(4) Toyoda & Yabe J. Phys. D: Appl. Phys.,1 6 (1983)