The opaque quality comes from quartz sands of high purity when reduced to a molten state at a temperature of
approximately 2000° C. The high temperature produces a vitreous material characterized by the presence of a multitude of
gaseous micro-bubbles. These bubbles diffract light, giving the material its opacity. The term opaque silica is mainly
used for molded or centrifuged parts, while the product obtained by drawing is normally referred to as translucent.

Opaque fused quartz trays are 99.95% pure Sio2. These trays may contain some black spots either in the wall of the tray
or on the surface. The spots are due to the method of fabrication and tooling. The opaque trays are a less expensive
option to higher purity clear fused quartz trays.

Opaque silica glass offers a number of exceptional properties, such as:

• Extreme Hardness
• Low Expansion
• Excellent High Temperature Resistance
• Maximum Continuous Temperature 1100° C
• Extreme Chemical Purity
• Excellent Corrosion Resistance
• Excellent Electrical Insulation Properties
• Remarkable Stability Under Atomic Bombardment