Group 1 - The article discusses the differences between quartz glass and ordinary glass, highlighting that quartz glass is made from over 99% pure silica, while ordinary glass contains 70%-75% silica along with other components [1][3] - Quartz glass is characterized by its high chemical stability, being inert to most acids except hydrofluoric and hot phosphoric acid, making it a suitable material for various chemical applications [3][4] - The thermal expansion coefficient of quartz glass is significantly lower than that of ordinary glass, being 5.5*10^-7/℃, which is 1/12 to 1/20 of ordinary glass [4] Group 2 - The article categorizes glass into flat glass and deep-processed glass, with flat glass further divided into three types: drawn glass, rolled glass, and float glass, with float glass becoming the mainstream manufacturing method due to its uniform thickness and ease of management [2] - Quartz glass exhibits unique optical properties, allowing it to transmit ultraviolet light and visible light, making it essential for high-stability optical systems in harsh environments [3][4]

Core Viewpoint - The article explores the fascinating history and production process of glass, highlighting its transformation from a rare luxury item to an essential part of everyday life [2][6]. Production Process - Glass is primarily made from sand, which consists mainly of silicon dioxide (SiO2). When combined with soda (sodium carbonate, Na2CO3), the melting temperature of silicon dioxide is lowered, allowing it to become a molten glass known as water glass (sodium silicate, Na2SiO3) [4]. - To achieve clear glass, iron must be absent from the raw materials; otherwise, the glass will take on a green hue. Various metal oxides can be added to create colored glass, such as cobalt oxide for blue, copper oxide for red, chromium oxide for green, and ferric oxide for brown [4]. Historical Context - Historically, glass was a luxury item reserved for royalty and nobility, but it has since become a common household item, used in mirrors, light bulbs, and various containers [6]. Applications - Ordinary glass, composed of Na₂SiO₃, CaSiO₃, and SiO₂, serves multiple functions, including providing shelter from the elements while allowing sunlight to enter. Techniques such as acid etching can create intricate designs on glass [9]. - Tempered glass, which is rapidly cooled after heating, is known for its safety features, breaking into small, blunt pieces rather than sharp shards [9]. - Quartz glass, made solely from silicon dioxide, is utilized in high-temperature and high-purity applications, such as in the production of high-performance glass fibers and semiconductor manufacturing [12].