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Glass is an amorphous (non-crystalline) solid. Because it is often transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made of glass like "a glass" of water, "glasses", and "magnifying glass", are named after the material. Glass is ...
Unless stated otherwise, the properties of fused silica (quartz glass) and germania glass are derived from the SciGlass glass database by forming the arithmetic mean of all the experimental values from different authors (in general more than 10 independent sources for quartz glass and T g of germanium oxide glass). The list is not exhaustive.
Glass typically has a tensile strength of 7 megapascals (1,000 psi). [1] However, the theoretical upper bound on its strength is orders of magnitude higher: 17 gigapascals (2,500,000 psi). This high value is due to the strong chemical Si–O bonds of silicon dioxide. Imperfections of the glass, such as bubbles, and in particular surface flaws ...
Glass block, also known as glass brick, is an architectural element made from glass used in areas where privacy or visual obscuration is desired while admitting light, such as underground parking garages, washrooms, and municipal swimming baths. Glass block was originally developed in the early 1900s to provide natural light in industrial ...
Tempered or toughened glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempering puts the outer surfaces into compression and the interior into tension. Such stresses cause the glass, when broken, to shatter into small granular chunks instead of ...
The history of glass-making dates back to at least 3,600 years ago in Mesopotamia. However, most writers claim that they may have been producing copies of glass objects from Egypt. [1] Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt. [2]
Cut glass wine glass made of lead glass. Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. [1] Lead glass contains typically 18–40% (by mass) lead(II) oxide (PbO), while modern lead crystal, historically also known as flint glass due to the original silica source, contains a minimum of 24% PbO. [2]
Obsidian talus at Obsidian Dome, California Polished snowflake obsidian, formed through the inclusion of cristobalite crystals. The Natural History by the Roman writer Pliny the Elder includes a few sentences about a volcanic glass called obsidian (lapis obsidianus), discovered in Ethiopia by Obsidius, a Roman explorer.