The ancient Romans also learned how to make glass after conquering Egypt.
About the 1st century BC, the ancient Romans developed the technology of glass blowing using iron pipes, using a metal pipe to blow molten glass into hollow bubbles, and finally making glassware of various shapes.
Scientific archeology has discovered that in the ancient city of Pompeii, which was buried by a volcanic eruption in AD 79, some buildings were found to have sheet glass mounted on bronze window frames. This is the earliest example of the use of glass as a building material for lighting a room. Due to the low melting point of glass at that time, there were a large number of unmelted particles and impurities in the glass, which caused the light to scatter, making the glass transparent and opaque. At the same time, the glass production process at that time was to cast and extrude glass liquid into glass plates, so the surface of the glass plates was uneven, which caused light scattering, which was one of the reasons that flat glass was transparent and opaque at that time.
In the Roman era, glassmaking technology improved even more. Previous glass was colored, most often light green, because it contained ferrous ions. The Romans discovered that adding manganese dioxide to glass made it colorless. It turns out that the tetravalent manganese in manganese dioxide is an oxidizing agent, and it will oxidize ferrous ions into yellow ferric ions, and be reduced to blue-violet trivalent manganese ions. Optically, yellow and violet can complement each other to a certain extent, and when they mix together to form white light, the glass appears colorless and transparent. However, after a few years, the trivalent manganese will continue to be oxidized by air, and the purple color will gradually increase, so the window panes of those old houses will be slightly purple. With colorless and transparent glass, the Romans used it in more places, they not only used glass to make containers, but also used it to make mosaic floor tiles.
Around the 4th century, the ancient Romans began to use glass for doors and windows.
During the period from the 11th to the 15th century, many varieties of glass were developed in Venice, such as architectural door and window glass, glass bottles, glassware, glass mirrors and other decorative glass. Inventions have improved many glass manufacturing processes.