Obsidian: Volcanic glass formed naturally. Used by prehistoric humans for tools, blades, and decorative items.
Fulgurite: Glass formed when lightning strikes sand.
Mesopotamia & Egypt: Glass first created as a byproduct of metalworking.
Early glass was opaque and colored; used in beads and amulets.
Techniques were rudimentary — glass was cast, molded, or pressed, not blown.
Glassblowing invented (~50 BCE) in Syria (possibly by Phoenicians). Revolutionized glass production:
Allowed for thin-walled vessels.
Made glassware more affordable and accessible.
Roman Empire:
Mass production of glass for domestic and architectural use.
Clear glass first produced by Romans (via manganese dioxide to remove color).
Used in windows, containers, and tableware.
Inherited Roman techniques and expanded on them.
Developed cut glass and refined decorative methods.
Famous centers: Syria, Persia, Egypt.
Venice (Murano) became a major center in the 13th century.
Masters developed cristallo, nearly colorless glass.
Trade secrets were closely guarded.
Stained Glass Windows in Gothic cathedrals (1100s–1300s).
Colored glass created with metal oxides.
Iconic in religious architecture across Europe.
Glass used in telescopes (Galileo, 1609), microscopes, and eyeglasses.
Development of precision lenses fueled scientific discovery (Scientific Revolution).
Invented by George Ravenscroft (England, ~1674).
Mixed lead oxide into glass for brilliance and easier cutting.
Basis of modern cut crystal.
Crown glass and cylinder methods for making window panes.
Pressed glass (USA, 1825): cheaper decorative glass via molds.
Bottles and jars mass-produced with semi-automatic machines.
Used for mirrors, shopfronts, and architecture.
Float glass not yet invented, so surfaces were polished by hand.
Invented by Sir Alastair Pilkington (UK).
Molten glass floated over molten tin = perfectly flat panes.
Revolutionized architecture and automotive industries.
Glass drawn into fine threads; used in insulation and composites.
Invented in early 20th century (Corning Inc.).
Resistant to thermal shock — ideal for labs and kitchens.
Tempered glass: heat-treated for safety.
Laminated glass: used in windshields.
Photochromic glass: lenses that darken in sunlight.
Electrochromic glass: changes transparency with voltage.
Used in energy-efficient buildings, cars, and privacy screens.
Chemically strengthened for mobile devices (by Corning, 2007).
Scratch-resistant and durable.
Fiber optics for internet and data.
Bioglass used in bone grafts and medical implants.
Ultra-clear glass used in solar panels and telescopes.