maurice van es
rooms of now
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shower
sunsetsbeforeiwasborn
jude
mire
cat
leadbeater
graveyard
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thesis
nicos
door
farm
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texel
kunstislang
lissabon2018
horse
books
seashell
mels
birthdays
hair1996
food
claricelispector
youngme
rixt
ego
kringloop
pancakes
rijksopen2018
father
see everything
What is Glass?
Glass is a non-crystalline, often transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda-lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term glass, in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material.
The history of glass-making dates back to at least 3,600 BC in Mesopotamia, however some claim they may have been producing copies of glass objects from Egypt. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt.[2] The earliest known glass objects, of the mid 2,000 BC, were beads, perhaps initially created as the accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing. Glass products remained a luxury until the disasters that overtook the late Bronze Age civilizations seemingly brought glass-making to a halt.
Development of glass technology in India may have begun in 1,730 BC. In Ancient China glass-making had a later start compared to ceramics and metal work.
From across the former Roman Empire archaeologists have recovered glass objects that were used in domestic, industrial and funerary contexts. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was even used in jewelry.
Naturally occurring glass, especially the volcanic glass obsidian, has been used by many Stone Age societies across the globe for the production of sharp cutting tools and, due to its limited source areas, was extensively traded. But in general, archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or ancient Egypt. Because of Egypt's favorable environment for preservation, the majority of well-studied early glass is found there, although some of this is likely to have been imported. The earliest known glass objects, of the mid-third millennium BC, were beads, perhaps initially created as accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing.
- Wikipedia