DeutschFused Silica vs Fused Quartz
The terms fused quartz and fused silica are often used interchangeably in the industry, and for most purchasing decisions they refer to the same family of high-purity SiO₂ glass. Technically, however, there is a distinction in how the glass is made:
- Fused quartz — produced by melting naturally occurring quartz crystal or sand. Trace mineral impurities from the natural raw material (mainly Al, Ti, Fe) are present at low levels.
- Fused silica — produced from synthetic silica precursors (for example SiCl₄ flame hydrolysis) or highly purified synthetic powder. Synthetic fused silica achieves the highest purity and the best deep-UV transmission, with very low bubble and inclusion content.
Practical Differences
| Aspect | Fused Quartz (natural) | Synthetic Fused Silica |
|---|---|---|
| Raw material | Natural quartz crystal | Synthetic silica precursor |
| Purity | High (grade dependent) | Highest |
| UV transmission | Good from ~220 nm (grade dependent) | Excellent, down to ~185 nm |
| Bubble / inclusion content | Low to very low | Extremely low |
| Typical uses | Furnace tubes, labware, industrial parts, general optics | Deep-UV optics, lithography, laser optics |
Which Do You Need?
For furnace tubes, boats, labware and most industrial components, natural fused quartz grades (JGS2/JGS3 class) offer the best balance of performance and cost. For deep-UV optics, laser applications or the most contamination-sensitive processes, synthetic fused silica is the right choice.
Note: GKLQuartz supplies parts in the grades we stock or can source; grade availability for synthetic fused silica should be confirmed with us before specifying. [Technical Information Required — grade availability confirmation]
