Fused Quartz is a result of melting synthetically derived silicon dioxide and is used in many of the same applications as fused silica. The main differences are that fused silica transmits better in the UV and fused quartz is lower in OH content. Both are highly pure, have high chemical resistance, good thermal shock resistance, and low thermal expansion coefficient. SGP can CNC mill, cut, drill, lap, and polish Fused Quartz into any dimension or surface finish.