History of Glass
Man-made glass was first produced in Mesopotamia in the early second millenium B.C. Early glass production was a time-consuming process in which mud and dung were used as the core around which the molten material hardened.
Glass is made from a mixture of silica obtained from fine sand or pulverized sandstone. In modern glass production, alkali is used to lower the melting point. The alkali is either a form of soda or potash depending on the quality of glass desired.
Properties of glass can be developed by adding other substances usually oxides. Depending on which substance is added the qualities of glass can be altered. Different characteristics of glass that are important to industry include: brilliance, weight, thermal and electrical resistence, refractive index, absorption of infrared rays and color.
Blown Glass
Blown glass made using a tube did not occur until sometime between 27 BC and 14 AD in Syria. This advancement transformed the material's usefulness into a mass-producible material which could be quickly inflated into large, leakproof vessels. Glassblowing spread throughout the world. Venice became a center for high quality glass manufactured in the late medieval period.Pressed Glass
The greatest achievement in the glass industy since Roman times began in the 1820's in America, the innovation of pressing glass.
Pressed Glass allowed for items to be produced more efficiently and cheaply for wider consumption by a growing middle class. Lancaster, Ohio was named the "Pressed Glass Capital of Ohio" by the State Legislature in 2002.
