S & R Optic GmbH
Enabling Crystal Optics Solutions

Quartz

Properties of Quartz

Quartz is the crystalline form of SiO2. Fused SiO2 (the non-crystalline form of SiO2) , also called fused quartz, is used in a huge variety of technical and consumer products, mainly because of the high melting temperature and it’s resistance to thermal shock. Very pure fused SiO2 is also commonly used in the optics industry, because of it’s excellent UV transmission.

Crystalline quartz is a uniaxial positively birefringent optical material. Because of it’s birefringence, it is used for polarizing components such as waveplates and polarizers. Although it’s birefringence is lower than that of mica, it is unpractical for the production of true zero order retardation plates because – unlike mica – it cannot be cleaved, and other optical production methods are not available for the required thinness of retardation plates.


Pure Quartz (crystalline SiO2) Properties

 

Property

 Unit

 c

 typ. / bulk

c

General

 

 


 

Colour



clear


Crystal structure



trigonal


Mechanical

 




Density

g/cm3


2.65


Hardness - Mohs



7


Shear modulus

GPa


31


Compressive strength

GPa


36


Modulus of elasticity

GPa

97.2


76.5

Thermal

 




Specific heat

J/(gK)


0.733


Thermal conductivity

W/(mK)

10.7


6.2

Coefficient of thermal expansion


 

Melting point

°C


1723


Boiling point

°C


2230


Electrical

 




Dielectric constant


4.34


4.27

Optical

 




Refractive index no (633 nm)



1.543


Refractive index ne (633 nm)



1.552


Birefringence (633 nm)



0.0091


Specific optical rotation

°/mm


21…28


 

The information contained herein is typical for crystalline quartz. As with all materials, quartz properties may vary slightly. Consequently S & R Optic does not make any warranties for any particular use or purpose.