Fused Silica vs Fused Quartz – Exact Differences in Raw Material, Purity & Application

Mar 3,2026

# Quartz Glass vs Borosilicate Glass – Full Comparison on Properties, Cost & Applications ## 1. Introduction Quartz glass and borosilicate glass are two mainstream heat-resistant glass materials widely adopted in laboratories, industrial production and optical equipment. Many engineers and purchasers mix up their features and make improper choices. This article conducts a comprehensive comparison covering material composition, core performance, service life, production cost and application fields, to help you select the most suitable material according to actual working conditions. ## 2. What Are Quartz Glass & Borosilicate Glass Quartz Glass: Dominated by high-purity SiO₂ without extra additives. It is manufactured by melting natural quartz crystal or synthetic silica under ultra-high temperature, and classified into industrial grade, optical grade and semiconductor grade for different usage demands. Borosilicate Glass (Pyrex): Formulated with silica, boron oxide and sodium oxide. Boron is added to improve heat resistance. As a cost-effective heat-resistant glass, it is widely used in civil fields and general industrial scenarios. 3. Key Properties

Comparison Item	Quartz Glass	Borosilicate Glass
Main Composition	99.5%~99.999% SiO₂	SiO₂ + B₂O₃ + Na₂O
Max Continuous Temperature	1100°C	450°C
Thermal Shock Resistance	Excellent, tolerate sharp temperature change	General, only for mild temperature fluctuation
Deep UV Transmittance	Full transmission down to 160nm	Almost completely block deep UV
Acid Resistance	Excellent	Good
Alkali Resistance	Poor to dilute alkali	Medium
Purity Level	Ultra-high purity, semiconductor available	Medium purity

4. Manufacturing Process Quartz Glass: Raw material purification → 1700~2000°C high-temperature melting → molding → stress relief annealing → precision processing & strict inspection. The whole process is complicated with high energy consumption and production cost. Borosilicate Glass: Raw material mixing → 800~1200°C melting → molding → simple natural cooling. Its production technology is mature, easy to operate and well controlled in cost. 5. Core Advantages Quartz Glass Advantages - Outstanding high temperature resistance for long-term service in industrial furnaces - Full-band deep UV transmission, exclusive choice for UV optical systems - Ultra-high material purity to prevent contamination in precision production - Stable physical and chemical performance under cyclic high-temperature conditions Borosilicate Glass Advantages - Low unit price and sufficient market supply - Light weight and easy for cutting and secondary processing - Fully meet the requirements of conventional heat-resistant application scenarios 6. Application Scenarios Choose Borosilicate Glass For - Ordinary laboratory beakers, flasks and daily heat-resistant glassware - Low-temperature industrial observation windows and civil heating appliances - General chemical experiments without UV transmission and ultra-high temperature demands Choose Quartz Glass For - Semiconductor diffusion furnaces and annealing processing equipment - UV sterilization, UV curing and deep ultraviolet optical instruments - High-temperature industrial furnaces and precision chemical reaction vessels - High-temperature optical components for aerospace and defense industries 7. Material Comparison & Selection Guide Cost & Service Life Borosilicate glass features low unit price, yet it tends to soften, deform and age above 500°C, leading to short service life in high-temperature environments. Quartz glass has a higher initial cost, while its service life can reach 2 to 5 years under standard industrial working conditions. For high-end industrial projects, it delivers lower overall comprehensive cost. Selection Rules - Working temperature ≤400°C & common laboratory use → Borosilicate Glass - Working temperature >450°C, UV transmission required or high purity demanded → Quartz Glass 8. FAQ Q1: Can borosilicate glass work above 500°C? A1: No. It will soften and deform when temperature exceeds 450°C, so it cannot be used for high-temperature furnaces. Q2: Which material is capable of transmitting ultraviolet light? A2: Only quartz glass supports deep ultraviolet transmission; borosilicate glass blocks UV rays completely. Q3: Which one is more economical? A3: Borosilicate glass is much cheaper than quartz glass. Q4: Can borosilicate glass replace quartz glass for semiconductor production? A4: No. Borosilicate glass contains high impurities and fails to meet ultra-clean standards for semiconductor manufacturing. 9. Conclusion Borosilicate glass is a cost-effective option for conventional low-temperature applications and general laboratory use. Quartz glass is irreplaceable in ultra-high temperature environments, UV optical systems and high-purity industrial processes. Define your requirements on temperature resistance, optical performance and material purity first, then select the proper glass material. 👉 Related Knowledge & Products: [Quartz Glass Tubes](link) | [What Is Quartz Glass?](link) | [Quartz Tube Temperature Limits](link) Author: Felix Glass Optical Engineering Team Reviewed By: Senior Optical Material Engineer Last Updated: June 2026 References: ISO 12123 Optical Glass Standards, Industrial Heat-Resistant Glass Application Manual

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