Quartz Glass

Special Properties

• Excellent ultraviolet light transmission
• High purity and optical performance
• Outstanding heat resistance of up to 1000 °C
• Low coefficient of thermal expansion
• Non-crystalline, amorphous glass
• Crystal-clear, water-white appearance
• Very high resistance against thermal shocks
• Exceptional chemical resistance
• High hardness and good scratch resistance
• Superb electrical insulator
• Low fluorescence
• Made by a flame hydrolysis process
• Machinable by cutting, grinding, and polishing

Typical Applications

• UV-transmitting window optics
• Quartz wafers for the semiconductor industry
• Substrates for mirror or filter coatings
• Laser optics
• UV measuring instruments
• Photomask blanks for semiconductor lithography
• Microscope slides and cover glasses for medical use
• Optical high-temperature applications
• Industrial automation
• Quartz plates for research laboratories
• Space applications

Get a price quote

Related Materials

• Fused Quartz
  (Natural fused quartz glass for sight glass applications)
• BOROFLOAT^®
  (High-temperature borosilicate glass from SCHOTT)

Optical Quartz Glass, known as Fused Silica

Quartz glass used for optics typically is synthetic fused silica. It is made by a flame hydrolysis process using raw materials of the highest purity. The crystal-clear amorphous glass is virtually free from inclusions and exclusively consists of silicon and oxygen. It is also referred to as silicon dioxide, or SiO₂.

Superb UV Transmission

As there are no metal ions or other contaminants present in the material that typically absorb UV light, optical quartz glass provides very high transmission for ultraviolet wavelengths. Already at 185 nm, more than 80% of light is transmitted. Furthermore, the chemical structure of the pure silicon dioxide in synthetic quartz glass is extremely homogeneous, which further minimizes absorption and scattering losses in the UV spectrum. This makes it the preferred material for demanding UV applications.

Outstanding Thermal Performance

Synthetic quartz glass exhibits outstanding thermal performance, primarily due to its exceptionally low coefficient of thermal expansion (CTE), high softening point, and excellent thermal shock resistance. It withstands temperatures up to 1000 °C or even above. Its high resistance to thermal shocks means it can be rapidly heated or cooled without cracking or breaking, a property that is critical for demanding optical, semiconductor, and aerospace applications.

Exceptional Chemical Resistance

As well, the chemical properties of quartz glass are remarkable. Its durability to acids exceeds that of most other glasses. Only phosphoric acid and hydrofluoric acid can attack the material. Moreover, optical quartz glass is exceptionally resistive to salt solutions and water. Optical quartz glass is also resistant to reactive gases and maintains its integrity under harsh chemical conditions, making it suitable for use in aggressive environments where other materials would degrade. Quartz glass is highly chemically resistant, making it ideal for applications requiring exposure to a wide range of corrosive chemicals and demanding environments.

Special Electrical Properties

Quartz glass is widely recognized for its outstanding electrical insulating properties. Since currents can only flow through mobile ionic impurities, which are only marginally present in quartz glass, it offers exceptionally high electrical resistivity and insulation resistance. It is an excellent insulator even under elevated thermal conditions. The material also features a low dielectric constant and maintains stable dielectric properties across a broad range of frequencies—up to the gigahertz range. These properties make optical quartz glass a preferred material for use in high-voltage, high-frequency, and precision electronics applications in industry.

We make quartz optics for the ultraviolet, visible, and infrared wavelength range, primarily from material blocks called boules. This raw material can be selected for even lower inclusions and bubbles. Furthermore, an index homogeneity as low as ≤ 0.5 ppm is possible if critical for an application. Cutting the raw glass from the boule is the first step in the production of a quartz glass optic. The raw material is then shaped and polished to meet specific requirements in terms of flatness and surface quality. Our company manufactures many UV-transparent windows, quartz glass wafers, microscope slides, quartz plates, and many other small and large optics daily.

Since there are different types of quartz glass, it is often difficult to find the appropriate material grade for a specific application, both in terms of technical requirements and price. That's why we created our Quartz Glass FAQ page, which provides additional information about the main different quartz glass types.

To get a quotation for optical quartz glass parts with individual dimensions, please select a thickness from the table or use the button below.

Get a price quote

48-hour custom express manufacturing

Specifications

Ultraviolet to infrared transmission
at 160–5000 nm @ 10 mm thickness

Show details

Typical transmission
at 185–700 nm @ 1 mm thickness

Show details

 

Standard Thicknesses

As high-purity quartz glass comes in blocks, there are usually no off-the-shelf standard thicknesses. Hence, the thickness must be individually specified and fabricated. However, we continuously grind and polish to different thicknesses and tolerances to offer our customers the best possible availability and very short lead times. These thicknesses have an optical-quality polishing finish. You can order them with individual dimensions and even take advantage of our 48-hour express service.

Click on a number below to start an inquiry:

Thickness (mm)	Tolerance
0.175	±0.020	✔
0.30	±0.050	✔
0.30	±0.025	✔
0.50	±0.050	✔
0.50	±0.030	✔
0.50	±0.025	✔
1.00	±0.100	✔
1.00	±0.025	✔
1.10	±0.100	✔
2.00	±0.150	✔
3.00	±0.200	✔
3.00	±0.025	✔
For any other thickness, please send us your inquiry.

 

Transmission

• T > 80% at 185 nm
  

Refractive index

• n_d = 1.4585

Density

• 2.20 g/cm³

Young's modulus

• 74 GPa (typical value)

Homogeneity

• Homogeneity classes per specification
• Index homogeneity down to ≤ 0.5 ppm is possible on demand

Inclusion classes

• Inclusion-class options are available

Glass composition

• Silicon dioxide (SiO2)

Operating temperature

• Up to 1000 °C

Average coefficient of thermal expansion

• ≈ 0.57 × 10^-6/K

Viscosity Temperatures

• Softening point: ≈ 1585 °C
• Annealing point: ≈ 1042 °C
• Strain point: ≈ 893 °C

Dielectric constant

• ε_r: 3.9 (500 MHz)

 

Fused Silica is not the same as Fused Quartz

In addition to the quartz glass for optics described in this data sheet, we also have a less sophisticated quartz glass type in our product range. It is referred to as natural quartz glass or Fused Quartz and is not as pure as the synthetic quartz glass. Although it also has the typical crystal-clear appearance, Fused Quartz glass transmits less light in the ultraviolet range but is also significantly more economical than Fused Silica. Even if it is generally not suitable for producing demanding optics, Fused Quartz is an ideal choice for industrial high-temperature sight glasses and applications that require high chemical resistance. For more details, please visit our Fused Quartz data sheet.

 

We process quartz materials from all leading manufacturers worldwide

Our company processes quartz glasses from nearly all leading manufacturers in the quartz glass industry worldwide (CORNING, Heraeus, Tosoh, SCHOTT, Saint-Gobain Quartz, Shin-Etsu, GE Quartz, and many others). For more detailed properties, data sheets, and information on all quartz glasses we process, please consider using our information request form or contact us by email.

 

All details and specifications given are average reference values and are not guaranteed. Please consider the notes on technical specifications.

© 1994–2025 Präzisions Glas & Optik GmbH

Last update: June 16, 2025