The Corning Museum of Glass

Top 10 Glass Facts
- Glassmaking began in Mesopotamia (now Iraq and northern Syria) just before 2000 B.C., more than 4000 years ago. The Museum’s earliest pieces date from about 1450 B.C.
- Glassblowers work with molten glass at temperatures near 2100º F (1150º C).
- Glass can be formed in nature when sand or rocks are heated to high temperatures then cooled rapidly. Volcanic glass is called obsidian, glass formed when a meteorite strikes sand is called a tektite, and glass formed from a lightning strike is called a fulgurite.
- There are many different recipes for making glass, but the three main ingredients are a former, flux and stabilizer. Silica (Silicon dioxide) in the form of sand is a common former. Soda (Sodium carbonate) and Potash (Potassium carbonate), both alkalis, are common fluxes which lower the melting point. Lime (calcium carbonate), is a common stabilizer needed to make the glass strong and water resistant.
- Glassblowing began in the Roman Empire around 50 B.C.
- Glass musical instruments include the armonica developed by Ben Franklin.
- Glassmaking was America’s first industry. Two unsuccessful attempts were made to start glass factories in Jamestown in 1608 and 1621.
- When gold chloride is added to a batch, the mixture of raw materials used to make glass, the result is a deep red glass known as gold ruby.
- In 1954, Corning scientist Donald Stookey left a piece of glass in a furnace and it overheated. Crystals formed in the glass, causing it to be opaque and very strong—a glass-ceramic. Today, glass-ceramics are commonly used as bakeware.
- Glass used in space capsules has been chemically tempered. Glass is placed in a bath of potassium salts where potassium ions replace the smaller sodium ions. This exchange makes the surface crowded and the glass is compressed, making it very strong.

