Although it technically depends on the exact molecular makeup of the glass in question, glass typically melts between 2,500 degrees Fahrenheit and 2,900 degrees F (approximately 1,400 - 1,600 degrees Celsius). Certain types of glass can melt at lower temperatures, but commercial glass must reach that approximate temperature before melting.
To form glass, it must be heated to these high temperatures in very hot furnaces. Most commercial glass is made from three raw materials: silica sand, soda ash and limestone. The four primary methods used to form glass once it has been melted are blowing, pressing, drawing and casting.