Dictionary Definition
glass
Noun
1 a brittle transparent solid with irregular
atomic structure
2 a glass container for holding liquids while
drinking [syn: drinking
glass]
3 the quantity a glass will hold [syn: glassful]
4 a small refracting telescope [syn: field glass,
spyglass]
5 amphetamine used in the form of a crystalline
hydrochloride; used as a stimulant to the nervous system and as an
appetite suppressant [syn: methamphetamine,
methamphetamine hydrochloride, Methedrine, meth, deoxyephedrine, chalk, chicken
feed, crank, ice, shabu, trash]
6 a mirror; usually a ladies' dressing mirror
[syn: looking
glass]
7 glassware collectively; "She collected old
glass"
Verb
1 furnish with glass; "glass the windows" [syn:
glaze]
2 scan (game in the forest) with binoculars
3 enclose with glass; "glass in a porch" [syn:
glass
in]
4 put in a glass container
5 become glassy or take on a glass-like
appearance; "Her eyes glaze over when she is bored" [syn: glaze, glass over,
glaze
over]
User Contributed Dictionary
English
Etymology
Old English glæs, cognate with Old Saxon and Old High German glas, which (in OHG) is attested as a gloss for electrum 'amber'. These words are developed from . Possibly ultimately from the Proto-Germanic root (compare glow).- A solid, transparent substance made by melting
sand with a mixture of
soda, potash and lime.
- The tabletop is made of glass.
- A vessel (especially
one made of glass) from which drinks may be drunk.
- Fill my glass with milk please.
- The quantity of liquid contained in such a vessel.
- Would you like a glass of milk.
- In the context of "physics|uncountable": Amorphous
(non-crystalline)
substance.
- A popular myth is that window glass actually is an extremely viscous liquid.
- A mirror.
- She adjusted her lipstick in the glass.
- The backboard.
- He got the rebound off of the glass.
- The clear protective screen surrounding a hockey rink.
- He fired the outlet pass off the glass.
Translations
substance
- Afrikaans: glas
- trreq Albanian
- Arabic: (zujāj)
- Aramaic:
- trreq Armenian
- Basque: beira
- Bengali: কাঁচ
- Bosnian: staklo
- Bulgarian: стъкло (stâklo)
- trreq Burmese
- Catalan: vidre
- Chinese: 玻璃 (bōlí)
- Croatian: staklo
- Czech: sklo
- Danish: glas
- Dutch: glas
- Esperanto: vitro
- Estonian: klaas
- Finnish: lasi
- French: verre
- Georgian: მინა (mina)
- German: Glas ^
- Greek: γυαλί (yalí) , ύαλος (íalos) , ύελος (íelos)
- Gujarati: શીશો
- Hebrew: זכוכית (zhuhit) , זגוגית (zgugit)
- Hindi: ग्लास (glās) , शीशा (šīšā)
- Hungarian: üveg
- Icelandic: gler
- Irish: gloine
- Italian: vetro
- Japanese: ガラス (garasu, 硝子)
- trreq Kannada
- Korean: 유리 (yuri)
- Kurdish: şûşe , cam , glas , belûr , ,
- Latin: vitrum
- Latvian: stikls
- trreq Lithuanian
- trreq Malay
- Malayalam: സ്ഫടികം, പളുങ്കുപാത്രം, ഗ്ലാസ
- Maori: karaihe, karāhe, karaehe
- Marathi: कांच
- trreq Nepali
- trreq Oriya
- Persian: (šīšeh)
- Polish: szkło
- Portuguese: vidro
- Punjabi: ਸ਼ੀਸ਼ਾ
- Romanian: sticlă
- Russian: стекло
- trreq Samoan
- Scottish Gaelic: gloinne , glainne
- Serbian:
- Slovak: sklo
- Slovene: steklo
- Spanish: cristal italbrac Spain, vidrio italbrac Latin America
- Swedish: glas
- Tagalog: salamin
- trreq Tahitian
- Thai: (gâew)
- trreq Tongan
- Turkish: cam
- Urdu: (glās) , (šīša)
- trreq Vietnamese
- Welsh: gwydr
- Yiddish: גלאָז (gloz) m|f
drinking vessel
- Arabic: (ka’s)
- Bosnian: čaša
- Bulgarian: чаша
- Catalan: got, vas,
- Chinese: 杯子 (bēizi)
- Croatian: čaša
- Czech: sklenice
- Danish: glas
- Dutch: glas
- Finnish: lasi
- French: verre ^
- Georgian: ჭიქა (č‘ik‘a)
- German: Glas ^
- Greek: ποτήρι
- Hebrew: כוס (kos)
- Hungarian: pohár
- Irish: gloine
- Italian: bicchiere
- Japanese: グラス
- Korean: 글라스 (geullaseu), 잔 (jan)
- Kurdish: perdaq , piyale , şûşe , glas , ,
- Latvian: glāze
- Persian: (līvān)
- Polish: szklanka , kieliszek (for alcoholic drinks)
- Portuguese: copo
- Romanian: pahar
- Russian: стакан
- Scottish Gaelic: glainne
- Serbian:
- Slovak: pohár
- Slovene: kozarec
- Spanish: vaso (s)
- Swedish: glas
- Tagalog: baso
- Thai: (gâew)
- Turkish: bardak
- Ukrainian: склянка (sklj'ánkə)
- Yiddish: גלאָז (gloz) m|f
amorphous non-crystalline substance
- Bosnian: staklo
- Bulgarian: стъкло (stâklo)
- Catalan: vidre
- Croatian: staklo
- Czech: sklo
- Dutch: glas
- Finnish: lasi
- French: verre
- Georgian: მინა (mina)
- German: Glas (de)
- Irish: gloine
- Japanese: ガラス
- Korean: 유리 (yuri)
- Kurdish: şûşe , glas , belûr , cam , ,
- Persian: (šīšeh)
- Polish: szkło
- Russian: стекло
- Scottish Gaelic: glainne
- Serbian:
- Spanish: vidrio
- Swedish: glas
- Tagalog: salamin
- Yiddish: גלאָז (gloz) m|f
mirror See mirror
Adjective
glass (no or )- Fragile.
- He has a glass ankle.
Verb
- To strike (someone), particularly in the face, with a drinking glass with the intent of causing injury.
Quotations
- 1987, John Godber, Bouncers
http://books.google.com/books?ie=UTF-8&hl=en&id=f6-WVMj0qCUC&pg=PA19&lpg=PA19&sig=NzO0yHs5eqCDoOPewNE31SvzBBw
- JUDD. Any trouble last night?
- LES. Usual. Couple of punks got glassed.
- JUDD. Any trouble last night?
- 2002, Geoff Doherty, A Promoters Tale
http://books.google.com/books?ie=UTF-8&hl=en&id=f6cHAVAMwk8C&pg=PA72&lpg=PA72&sig=NN6mhVE1htG-CUB-GekL3ZWPIMw
- I often mused on what the politicians or authorities would say if they could see for themselves the horrendous consequences of someone who’d been glassed, or viciously assaulted.
- 2003, Mark Surdy, Pulp
http://books.google.com/books?ie=UTF-8&hl=en&id=sdF52lBdu3AC&pg=PA139&lpg=PA139&sig=o2nzWpBQX4v0Csr5DLGgTJrCy5c
- One night he was in this nightclub in Sheffield and he got glassed by this bloke who’d been just let out of prison that day.
Interjection
glass- A warning called out to alert teammates that a shot is about to
rebound off the backboard.
- The point guard launched a wobbly attempt at a three-pointer and immediately called "Glass!"
Derived terms
- cheval glass
- glassblower
- glassblowing
- glasses
- glassformer
- glass frog
- glasshouse
- glassiness
- glassless
- glassmaker
- glassware
- glasswork
- glassy
- looking glass
See also
Swedish
Pronunciation
Noun
glassExtensive Definition
this the
material
Glass in the common sense refers to a hard, brittle, transparent
solid, such as used for
windows, many bottles, or
eyewear, including
soda-lime
glass, acrylic
glass, sugar glass,
isinglass
(Muscovy-glass), or aluminium
oxynitride.
In the technical sense, glass is an inorganic
product of fusion which has been cooled to a rigid condition
without crystallizing. Many glasses contain silica as their main component
and glass former.
In the scientific sense the term glass is often
extended to all amorphous
solids (and melts that easily form amorphous solids), including
plastics, resins, or other silica-free
amorphous solids. In addition, besides traditional melting
techniques, any other means of preparation are considered, such as
ion
implantation, and the sol-gel method.
glass]]
Ordinary glass is prevalent due to its
transparency to visible
light. This transparency is due to an absence of electronic
transition
states in the range of visible light. The homogeneity of the
glass on length scales greater than the wavelength of visible light
also contributes to its transparency as heterogeneities would cause
light to be scattered, breaking up any
coherent image transmission. Many household objects are made of
glass. Drinking glasses,
bowls and
bottles are
often made of glass, as are light bulbs,
mirrors, aquaria, cathode
ray tubes, computer flat
panel displays, and windows.
In research laboratories, flasks,
test
tubes, and other laboratory
equipment are often made of borosilicate
glass for its low
coefficient of thermal expansion, giving greater resistance to
thermal
shock and greater accuracy in measurements. For
high-temperature applications, quartz glass
is used, although it is very difficult to work. Most laboratory
glassware is mass-produced,
but large laboratories also keep a glassblower on staff for
preparing custom made glass equipment.
Sometimes, glass is created naturally from
volcanic lava, lightning strikes, or meteorite impacts (e.g.,
Lechatelierite,
Fulgurite,
Darwin
Glass, Volcanic
Glass, Tektites). If
the lava is felsic this
glass is called obsidian, and is usually black
with impurities. Obsidian is a raw material for flintknappers, who have
used it to make extremely sharp glass knives
since the stone
age.
Glass sometimes occurs in nature resulting from
human activity, for example trinitite (from nuclear
testing) and beach
glass.
Glass in buildings
Glass is commonly used in buildings as transparent windows, internal glazed partitions, and as architectural features. It is also possible to use glass as a structural material, for example, in beams and columns, as well as in the form of "fins" for wind reinforcement, which are visible in many glass frontages like large shop windows. Safe load capacity is, however, limited; although glass has a high theoretical yield stress, it is very susceptible to brittle (sudden) failure, and has a tendency to shatter upon localized impact. This particularly limits its use in columns, as there is a risk of vehicles or other heavy objects colliding with and shattering the structural element. One well-known example of a structure made entirely from glass is the northern entrance to Buchanan Street subway station in Glasgow.Glass in buildings can be of a safety type,
including wired, heat strengthened (tempered) and laminated glass.
Glass fibre insulation is common in roofs and walls. Foamed glass,
made from waste glass, can be used as lightweight, closed-cell
insulation. As insulation, glass (e.g., fiberglass) is also used. In
the form of long, fluffy-looking sheets, it is commonly found in
homes. Fiberglass insulation is used particularly in attics, and is
given an R-rating, denoting the insulating ability.
Technological applications
Pure SiO2 glass
(the same chemical compound as quartz, or, in its polycrystalline form,
sand) does not absorb
UV light and is used for applications
that require transparency in this region. Large natural single
crystals of quartz are pure silicon dioxide, and upon crushing are
used for high quality specialty glasses. Synthetic amorphous
silica, an almost 100 % pure form of quartz, is the raw
material for the most expensive specialty glasses, such as optical
fiber core.
Undersea cables have sections doped with erbium, which amplify
transmitted signals by laser emission from within the
glass itself. Amorphous SiO2 is also used as a dielectric material in
integrated
circuits due to the smooth and electrically neutral interface
it forms with silicon.
Optical
instruments such as glasses, cameras, microscopes,
telescopes,
and planetaria are
based on glass lenses,
mirrors, and prisms.
The glasses used for making these instruments are categorized using
a six-digit glass code, or
alternatively a letter-number code from the Schott Glass
catalogue. For example, BK7 is a low-dispersion
borosilicate
crown
glass, and SF10 is a high-dispersion dense flint glass.
The glasses are arranged by composition, refractive index, and
Abbe
number.
Glass polymerization is a
technique that can be used to incorporate additives that modify the
properties of glass that would otherwise be destroyed during high
temperature preparation. Sol gel is an
example of glass polymerization and enables embedding of organic
and bioactive molecules, to add a new level of functionality to
glass.
Glass production
Glass production history
Glass melting technology has passed through
several stages:
- Glass was manufactured in open pits, ca. 3000 B.C. until the invention of the blowpipe in ca. 250 B.C.
- The mobile wood-fired melting pot furnace was used until around the 17th century by traveling glass manufacturers.
- Around 1688, a process for casting glass was developed, which led to glass becoming a much more commonly used material.
- The local pot furnace, fired by wood and coal was used between 1600 and 1850.
- The cylinder method of creating flat glass was used in the United States of America for the first time in the 1820s. It was used to commercially produce windows.
- The invention of the glass pressing machine in 1827 allowed the mass production of inexpensive glass products.
- The gas-heated melting pot and tank furnaces dating from 1860, followed by the electric furnace of 1910.
- Hand-blown sheet glass was replaced in the 20th century by rolled plate glass.
- The float glass process was invented in the 1950s.
Glass ingredients
Pure silica (SiO2) has a "glass
melting point"— at a viscosity of
10 Pa·s
(100 P)— of over
2300 °C
(4200 °F). While pure
silica can be made into glass for special applications (see
fused
quartz), other substances are added to common glass to simplify
processing. One is sodium
carbonate (Na2CO3), which lowers the melting point to about
1500 °C (2700 °F) in soda-lime
glass; "soda" refers to
the original source of sodium carbonate in the soda ash
obtained from certain plants. However, the soda makes the glass
water soluble, which is usually undesirable, so lime
(calcium
oxide (CaO), generally obtained from limestone), some magnesium
oxide (MgO) and aluminium oxide are added to provide for a better
chemical durability. The resulting glass contains about 70 to 74
percent silica by weight and is called a soda-lime
glass.
For obtaining the desired glass composition, the
correct raw material mixture (batch) must be determined by glass
batch calculation.
Contemporary glass production
Following the glass batch
preparation and mixing the raw materials are transported to the
furnace. Soda-lime
glass for mass production is melted in gas
fired units. Smaller scale furnaces for specialty glasses
include electric melters, pot furnaces and day tanks. Evaporation
losses during glass melting should be considered during the
selection of the raw materials, e.g., sodium selenite may be
preferred over easily evaporating SeO2.
Also, more readily reacting raw materials may be preferred over
relatively inert ones,
such as Al(OH)3
over Al2O3.
Usually, the melts are carried out in platinum crucibles to reduce
contamination from the crucible material. Glass homogeneity is achieved
by homogenizing the raw materials mixture (glass batch),
by stirring the melt, and by crushing and re-melting the first
melt. The obtained glass is usually annealed
to prevent breakage during processing.
Silica-free glasses
Besides common silica-based glasses, many other inorganic and organic materials may also form glasses, including plastics (e.g., acrylic glass), carbon, metals, carbon dioxide (see below), phosphates, borates, chalcogenides, fluorides, germanates (glasses based on GeO2), tellurites (glasses based on TeO2), antimonates (glasses based on Sb2O3), arsenates (glasses based on As2O3), titanates (glasses based on TiO2), tantalates (glasses based on Ta2O5), nitrates, carbonates and many other substances. In 2006 Italian scientists created an amorphous phase of carbon dioxide using extreme pressure. The substance was named amorphous carbonia(a-CO2) and exhibits an atomic structure resembling that of Silica.The physics of glass
The standard definition of a glass (or vitreous solid) requires the
solid phase to be formed by rapid melt quenching.. By definition as
an amorphous
solid, the atomic structure of a glass lacks any long range
translational
periodicity. However, by virtue of the local chemical
bonding constraints glasses do possess a high degree of
short-range order with respect to local atomic polyhedra. It is deemed that
the bonding structure of glasses, although disordered, has the same
symmetry signature (Hausdorff-Besicovitch
dimensionality) as for crystalline materials.
Glass versus a supercooled liquid
Glass is generally treated as an amorphous
solid rather than a liquid, though both views can be justified.
However, the notion that glass flows to an appreciable extent over
extended periods of time is not supported by empirical research or
theoretical analysis (see
viscosity of amorphous materials). From a more commonsense
point of view, glass should be considered a solid since it is rigid
according to everyday experience.
Some people believe glass is a liquid due to its
lack of a first-order phase
transition where certain thermodynamic variables
such as volume, entropy and enthalpy are continuous through
the glass transition temperature. However, the glass transition
temperature may be described as analogous to a second-order phase
transition where the intensive thermodynamic variables such as the
thermal
expansivity and heat
capacity are discontinuous. Despite this, thermodynamic phase
transition theory does not entirely hold for glass, and hence the
glass transition cannot be classed as a genuine thermodynamic phase
transition. There is also the problem that a supercooled liquid is
still a liquid and not a solid but it is below the freezing point
of the material and will crystallize almost instantly if a crystal
is added as a core. The
change in heat
capacity at a glass
transition and a melting
transition of comparable materials are typically of the same
order of magnitude indicating that the change in active degrees
of freedom is comparable as well. Both in a glass and in a
crystal it is mostly only the vibrational degrees of freedom
that remain active, whereas rotational and translational
motion becomes impossible explaining why glasses and crystalline
materials are hard.
Behavior of antique glass
The observation that old windows are often
thicker at the bottom than at the top is often offered as
supporting evidence for the view that glass flows over a matter of
centuries. It is then assumed that the glass was once uniform, but
has flowed to its new shape, which is a property of liquid. The
likely source of this unfounded belief is that when panes of glass
were commonly made by glassblowers, the technique
used was to spin molten glass so as to create a round, mostly flat
and even plate (the Crown
glass process, described above). This plate was then cut to fit
a window. The pieces were not, however, absolutely flat; the edges
of the disk would be thicker because of centripetal
force relaxation. When actually installed in a window frame,
the glass would be placed thicker side down for the sake of
stability and visual sparkle. Occasionally such glass has been
found thinner side down or on either side of the window's edge, as
would be caused by carelessness at the time of installation.
Mass production of glass window panes in the
early twentieth century caused a similar effect. In glass
factories, molten glass was poured onto a large cooling table and
allowed to spread. The resulting glass is thicker at the location
of the pour, located at the center of the large sheet. These sheets
were cut into smaller window panes with nonuniform thickness.
Modern glass intended for windows is produced as float glass
and is very uniform in thickness.
Several other points exemplify the misconception
of the 'cathedral glass' theory:
- Writing in the American Journal of Physics, physicist Edgar D. Zanotto states "...the predicted relaxation time for GeO2 at room temperature is 1032 years. Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer".
- If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed. Similarly, prehistoric obsidian blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass). 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 Tg of germanium oxide glass). Those values marked in italic font have been interpolated from sililar glass compositions (see Calculation of glass properties) due to the lack of experimental data.
Color
Colors in glass may be obtained by addition of coloring ions that are homogeneously distributed and by precipitation of finely dispersed particles (such as in photochromic glasses). Manganese dioxide can be added in small amounts to remove the green tint given by iron(II) oxide.History
- see also category Glass history
"The tradition is that a merchant ship laden with
nitrum being
moored at this place, the merchants were preparing their meal on
the beach, and not having stones to prop up their pots, they used
lumps of nitrum from the ship, which fused and mixed with the sands
of the shore, and there flowed streams of a new translucent liquid,
and thus was the origin of glass."
This account is more a reflection of Roman
experience of glass production, however, as white silica sand from
this area was used in the production of Roman glass due to its low
impurity levels. But in general archaeological evidence suggests
that the first true glass was made in coastal north Syria, Mesopotamia or
Old
Kingdom Egypt. Due to Egypt's favourable environment for
preservation, the majority of well-studied early glass is found in
Egypt, 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.
During the Late Bronze
Age in Egypt and Western Asia
there was an explosion in glass-making technology. Archaeological
finds from this period include coloured glass ingots, vessels (often coloured
and shaped in imitation of highly prized wares of semi-precious
stones) and the ubiquitous beads. The alkali of Syrian and Egyptian
glass was soda ash, sodium
carbonate, which can be extracted from the ashes of many plants,
notably halophile
seashore plants: (see saltwort). The earliest vessels
were 'core-wound', produced by winding a ductile rope of metal
round a shaped core of sand and clay over a metal rod, then fusing
it with repeated reheatings. Threads of thin glass of different
colours made with admixtures of oxides were subsequently wound
around these to create patterns, which could be drawn into festoons
with a metal raking tools. The vessel would then be rolled flat
('marvered') on a slab in order to press the decorative threads
into its body. Handles and feet were applied separately. The rod
was subsequently allowed to cool as the glass slowly annealed and was
eventually removed from the centre of the vessel, after which the
core material was scraped out. Glass shapes for inlays were also often created in
moulds. Much early glass production, however, relied on grinding
techniques borrowed from stone working. This meant that the glass
was ground and carved in a cold state. By the 15th century BC
extensive glass production was occurring in Western Asia
and Egypt. It
is thought the techniques and recipes required for the initial
fusing of glass from raw materials was a closely guarded
technological secret reserved for the large palace industries of
powerful states. Glass workers in other areas therefore relied on
imports of pre-formed glass, often in the form of cast ingots such
as those found on the Ulu Burun
shipwreck off the coast of Turkey.
Glass remained a luxury material, and the
disasters that overtook Late Bronze Age civilisations seem to have
brought glass-making to a halt. It picked up again in its former
sites, in Syria and Cyprus, in the ninth century BC, when the
techniques for making colourless glass were discovered. In Egypt
glass-making did not revive until it was reintroduced in Ptolemaic
Alexandria. Core-formed vessels and beads were still widely
produced, but other techniques came to the fore with
experimentation and technological advancements. During the Hellenistic
period many new techniques of glass production were introduced and
glass began to be used to make larger pieces, notably table wares.
Techniques developed during this period include 'slumping' viscous (but not fully molten)
glass over a mould in order to form a dish and 'millefiori' (meaning
'thousand flowers') technique, where canes of multi-coloured glass
were sliced and the slices arranged together and fused in a mould
to create a mosaic-like effect. It was also during this period that
colourless or decoloured glass began to be prized and methods for
achieving this effect were investigated more fully. During the
first century BC glass
blowing was discovered on the Syro-Palestinian coast,
revolutionising the industry and laying the way for the explosion
of glass production that occurred throughout the Roman world. Over
the next 1000 years glass making and working continued and spread
through southern Europe and beyond.
South Asia
Indigenous development of glass technology in South Asia may have begun in 1730 BCE. Evidence of this culture includes a red-brown glass bead along with a hoard of beads dating to 1730 BCE, making it the earliest attested glass from the Indus Valley locations. Some of the texts which mention glass in India are the Shatapatha Brahmana and Vinaya Pitaka.Romans
A full discussion of Roman glass making and
working can be found on the Roman glass
page.
Anglo-Saxon world
Evidence for glass making, working and use in the
5th to 8th centuries in England is discussed in the Anglo-Saxon
glass page.
Islamic world
In the medieval
Islamic world, the first clear, colourless, high-purity glasses
were produced by Muslim
chemists, architects
and
engineers in the 9th century. Examples include Silica glass
and colourless high-purity glass invented by Abbas Ibn
Firnas (810-887), who was the first to produce glass from
sand and stones.
The Arab poet
al-Buhturi
(820-897) described the clarity of such glass, "Its colour hides
the glass as if it is standing in it without a container."
Stained
glass was also first produced by Muslim
architects in Southwest
Asia using coloured glass rather than stone. In the 8th
century, the Arab chemist Jabir ibn Hayyan
(Geber) scientifically described 46 original recipes for producing
coloured glass in Kitab al-Durra al-Maknuna (The Book of the Hidden
Pearl), in addition to 12 recipes inserted by al-Marrakishi in a
later edition of the book.
The parabolic
mirror was first described by Ibn Sahl in his
On the Burning Instruments in the 10th century, and later described
again in Ibn
al-Haytham's On Burning Mirrors and Book of
Optics (1021). By the 11th century, clear glass mirrors were being produced in
Islamic
Spain. The first glass factories were also built by
Muslim craftsmen in the Islamic world. The first glass factories in
Christian
Europe were later built in the 11th century by Muslim Egyptian craftsmen in
Corinth,
Greece.
Medieval Europe
Glass objects from the 7th and 8th centuries have
been found on the island of Torcello near
Venice.
These form an important link between Roman times and the later
importance of that city in the production of the material. Around
1000 AD, an important technical breakthrough was made in
Northern Europe when soda glass, produced from white pebbles and
burnt vegetation was replaced by glass made from a much more
readily available material: potash obtained from wood ashes.
From this point on, northern glass differed significantly from that
made in the Mediterranean area, where soda remained in common
use.
Until the 12th century, stained
glass -- glass to which metallic or other impurities had been
added for coloring -- was not widely used.
The 11th century saw the emergence in Germany of new ways
of making sheet glass by blowing spheres. The spheres were swung
out to form cylinders and then cut while still hot, after which the
sheets were flattened. This technique was perfected in 13th century
Venice.
The Crown
glass process was used up to the mid-19th century. In this
process, the glassblower would spin
approximately 9 pounds
(4 kg) of molten glass at the end of a rod until it
flattened into a disk approximately 5 feet
(1.5 m) in
diameter. The disk would then be cut into panes.
Late medieval Northern Europe
Glass making in late medieval Northern Europe is
discussed in the article on Forest
glass.
Murano glassmaking
The center for glassmaking from the 14th century was the island of Murano, which developed many new techniques and became the center of a lucrative export trade in dinnerware, mirrors, and other luxury items. What made Venetian Murano glass significantly different was that the local quartz pebbles were almost pure silica, and were ground into a fine clear sand that was combined with soda ash obtained from the Levant, for which the Venetians held the sole monopoly. The clearest and finest glass is tinted in two ways: firstly, a small or large amount of a natural coloring agent is ground and melted with the glass. Many of these coloring agents still exist today; for a list of coloring agents, see below. Black glass was called obsidianus after obsidian stone. A second method is apparently to produce a black glass which, when held to the light, will show the true color that this glass will give to another glass when used as a dye.The Venetian ability to produce this superior
form of glass resulted in a trade advantage over other glass
producing lands. Murano’s reputation
as a center for glassmaking was born when the Venetian Republic,
fearing fire might burn down the city’s mostly wood buildings,
ordered glassmakers to move their foundries to Murano in 1291.
Murano's glassmakers were soon the island’s most prominent
citizens. Glassmakers were not allowed to leave the Republic. Many
took a risk and set up glass furnaces in surrounding cities and as
far afield as England and the Netherlands.
Glass art
Beginning in the late 20th century, glass started
to become highly collectible as art. Works of art in glass can be
seen in a variety of museums, including the Chrysler Museum, the
Museum of Glass in Tacoma, the Metropolitan Museum of Art, the
Toledo Museum of Art, and Corning
Museum of Glass, in Corning, NY,
which houses the world's largest collection of glass art and
history, with more than 45,000 objects in its collection.
Several of the most common techniques for
producing glass art include: blowing,
kiln-casting, fusing, slumping, pate-de-verre, flame-working,
hot-sculpting and cold-working. Cold work includes traditional
stained
glass work as well as other methods of shaping glass at room
temperature. Glass can also be cut with a diamond saw, or copper
wheels embedded with abrasives, and polished to give gleaming
facets; the technique used in creating waterford
crystal . Art is sometimes etched into glass via the use of
acid, caustic, or abrasive substances. Traditionally this was done
after the glass was blown or cast. In the 1920s a new mould-etch
process was invented, in which art was etched directly into the
mould, so that each cast piece emerged from the mould with the
image already on the surface of the glass. This reduced
manufacturing costs and, combined with a wider use of colored
glass, led to cheap glassware in the 1930s, which later became
known as Depression glass. As the types of acids used in this
process are extremely hazardous, abrasive methods have gained
popularity.
Objects made out of glass include not only
traditional objects such as vessels (bowls, vases, bottles, and other containers),
paperweights,
marbles, beads, but an endless range of
sculpture and
installation art as well. Colored glass is often used, though
sometimes the glass is painted, innumerable examples exist of the
use of stained
glass.
The
Harvard Museum of Natural History has a collection of extremely
detailed models of flowers made of painted glass. These were
lampworked by
Leopold
Blaschka and his son Rudolph, who never revealed the method he
used to make them. The Blaschka Glass
Flowers are still an inspiration to glassblowers today.
See also
References
Bibliography
- Noel C. Stokes; The Glass and Glazing Handbook; Standards Australia; SAA HB125–1998
- Brugmann, Birte. Glass Beads from Anglo-Saxon Graves: A Study on the Provenance and Chronology of Glass Beads from Anglo-Saxon Graves, Based on Visual Examination. Oxbow Books, 2004. ISBN 1-84217-104-6
- High Definition Archaeology: Threads Through the Past
- An Encyclopaedia of Indian Archaeology
External links
- Glass Encyclopedia - A comprehensive guide to all types of antique and collectable glass, with information, pictures and references
- Free information and articles about Designer Glassware, Vintage Art Glass, Depression Glass & Collectible Glass | JustGlass-Online.com
- The Canadian Museum of Civilization - The Story of Glass Making in Canada
- Corning Museum of Glass
- A comprehensive guide to art glass and crystal around the world
- Working Description Furnace & Moleria - Murano Glass
- Informative website about the glass industry
- Substances used in the Making of Colored Glass
- Glass property measurement and calculation
- Almost 400 articles and images about glass (mostly art glass)
glass in Afrikaans: Glas
glass in Arabic: زجاج
glass in Guarani: Itavera
glass in Belarusian: Шкло
glass in Bosnian: Staklo
glass in Bulgarian: Стъкло
glass in Catalan: Vidre
glass in Czech: Sklo
glass in Welsh: Gwydr
glass in Danish: Glas
glass in German: Glas
glass in Estonian: Klaas
glass in Modern Greek (1453-): Γυαλί
glass in Spanish: Vidrio
glass in Esperanto: Vitro
glass in Basque: Beira
glass in Persian: شیشه
glass in French: Verre
glass in Galician: Vidro
glass in Korean: 유리
glass in Croatian: Staklo
glass in Ido: Vitro
glass in Indonesian: Kaca
glass in Ossetian: Авг
glass in Icelandic: Gler
glass in Italian: Vetro
glass in Hebrew: זכוכית
glass in Kurdish: Cam
glass in Latin: Vitrum
glass in Latvian: Stikls
glass in Lithuanian: Stiklas
glass in Lombard: Véder
glass in Hungarian: Üveg
glass in Macedonian: Стакло
glass in Maltese: Ħġieġ
glass in Malay (macrolanguage): Kaca
glass in Dutch: Glas
glass in Japanese: ガラス
glass in Neapolitan: Vrito
glass in Norwegian: Glass (materiale)
glass in Norwegian Nynorsk: Glas
glass in Occitan (post 1500): Veire
glass in Uighur: ئەينەك
glass in Polish: Szkło
glass in Portuguese: Vidro
glass in Romanian: Sticlă
glass in Quechua: Q'ispillu
glass in Russian: Стекло
glass in Simple English: Glass
glass in Slovak: Sklo
glass in Slovenian: Steklo
glass in Serbian: Стакло
glass in Serbo-Croatian: Staklo
glass in Finnish: Lasi
glass in Swedish: Glas
glass in Tamil: கண்ணாடி
glass in Thai: แก้ว
glass in Vietnamese: Thủy tinh
glass in Turkish: Cam
glass in Ukrainian: Скло
glass in Venetian: Véro
glass in Yiddish: גלאז
glass in Contenese: 玻璃
glass in Chinese: 玻璃
Synonyms, Antonyms and Related Words
CM-glass, CR-glass, achromatic lens, adobe, aerological instrument,
agate glass, alabaster, aneroid barometer,
aneroidograph,
astigmatic lens, barograph, barometer, barometrograph, beaker, bifocals, bijouterie, billiard table,
binoculars, biscuit, bisque, blown glass, board, bottle glass, bowl, bowling alley, bowling green,
brick, bubble, bullet-resisting glass,
burning glass, camera,
camphor glass, carnival glass, cement, ceramic ware, ceramics, cheval glass,
china, clapboard, clear as glass,
coated lens, concave lens, concave mirror, concavo-convex lens,
condenser, convex
lens, convex mirror, coralene, costume jewelry,
crock, crockery, crown glass, crystal, cut glass, diaphane, display case,
distorting mirror, eggshell, enamelware, eyeglass, eyeglasses, eyepiece, face, fiber glass, field glass,
firebrick, flat, frosted glass, glass house,
glasses, glasslike, glassware, glassy, glaze, goblet, goggles, ground glass, hand
lens, hand mirror, house of cards, hurricane-hunter aircraft,
hyalescent, hyaline, hygrometer, ice, image, ivory, jewelry, jug, junk jewelry, laminated glass,
lath, lens, level, light, looking glass, lorgnette, lorgnon, magnifier, magnifying glass,
mahogany, marble, matchwood, meniscus, mercury, microscope, mirror, object glass, objective, objective prism,
ocular, old paper,
opaline, opera glasses,
pane, paper, parchment, paste, piecrust, pier glass, plane, plank, plate glass, porcelain, pot, pottery, prism, radiosonde, reader, reading glass, rear-view
mirror, recording barometer, reflector, refractory, revet, rhinestone, safety glass,
satin, scatter pins,
scope, seeing glass,
shake, shaving mirror,
sheathe, shingle, shopwindow, showcase, silk, slate, slide, smooth, specs, spectacles, speculum, spy glass, spyglass, stained glass,
stemware, stone, telephoto lens, telescope, tennis court,
terrestrial telescope, thatch, thermal detector,
thermometer,
thermostat, tile, tiling, toric lens, transparent
substance, trifocals,
tumbler, urn, vacuometer, varifocal lens,
vase, velvet, veneer, vitreous, vitrics, vitriform, vitrine, wall in, wall up,
wallpaper, watch
crystal, watch glass, weather balloon, weather instrument, weather
satellite, weather vane, weatherboard, weatherglass, window, window glass, window
mirror, windowlight,
windowpane, zoom
binoculars, zoom lens