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[Help us with translations!] Work at Wikipedia. Glass From Wikipedia, the free encyclopediaJump to: navigation, search This article is about the material. For other uses, see Glass (disambiguation). Moldavite, a natural glass formed by meteorite impact, from Besednice, Bohemia A modern greenhouse in Wisley Garden, England, made from float glass Clear glass light bulbGlass is an amorphous (non-crystalline) solid material. Gl asses are typically brittle, and often optically transparent. Glass is commonly used for windows, bottles, and eyewear; examples of glassy materials include sod a-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, and aluminium oxynitride. The term glass developed in the late Roman Empire. It was in the Roman glassmaking center at Trier, now in modern Germany, that the lateLatin term glesum originated, probably from a Germanic word for a transparent, l ustrous substance.[1] Strictly speaking, a glass is defined as an inorganic product of fusion which ha s been cooled through its glass transition to the solid state without crystallis ing.[2][3][4][5][6] Many glasses contain silica as their main component and glas s former.[7] The term "glass" is, however, often extended to all amorphous solid s (and melts that easily form amorphous solids), including plastics, resins, or other silica-free amorphous solids. In addition, besides traditional melting tec hniques, any other means of preparation are considered, such as ion implantation , and the sol-gel method.[7] Commonly, glass science and physics deal only with inorganic amorphous solids, while plastics and similar organics are covered by p olymer science, biology and further scientific disciplines. Glass plays an essential role in science and industry. The optical and physical properties of glass make it suitable for applications such as flat glass, contai ner glass, optics and optoelectronics material, laboratory equipment, thermal in sulator (glass wool), reinforcement fiber (glass-reinforced plastic, glass fiber reinforced concrete), and art. Contents [hide] 1 History 2 Glass production 2.1 Glass ingredients 2.1.1 Composition and properties 2.2 Contemporary glass production 2.3 Glassmaking in the laboratory 2.4 Sol-gel science/technology 3 Silica-free glasses 4 Physics of glass 4.1 Glass versus a supercooled liquid 4.2 Behavior of antique glass 4.3 Physical properties 4.3.1 Optical properties 4.3.2 Color 4.3.3 Optical waveguides 5 Modern glass art 5.1 Museums 6 See also 7 References 8 Bibliography 9 External links [edit] History Main article: History of glass The history of creating glass can be traced back to 3500 BCE in Mesopotamia.

[edit] Glass production Main articles: Glass production and Float glass [edit] Glass ingredients Quartz sand (silica) as main raw material for commercial glass production Oldest mouth-blown window-glass in Sweden (Kosta Glasbruk, Småland, 1742). In the middle is the mark from the glassblower's pipe.Pure silica (SiO2) has a "glass m elting point" at a viscosity of 10 Pa·s (100 P) of over 2300 °C (4200 °F). While pure sili ca can be made into glass for special applications (see fused quartz), other sub stances are added to common glass to simplify processing. One is sodium carbonat e (Na2CO3), which lowers the melting point to about 1500 °C (2700 °F) in soda-lime g lass; "soda" refers to the original source of sodium carbonate in the soda ash o btained from certain plants. However, the soda makes the glass water soluble, wh ich is usually undesirable, so lime (calcium oxide (CaO), generally obtained fro m limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added t o provide for a better chemical durability. The resulting glass contains about 7 0 to 74% silica by weight and is called a soda-lime glass.[8] Soda-lime glasses account for about 90% of manufactured glass. Most common glass has other ingredients added to change its properties. Lead gla ss or flint glass, is more 'brilliant' because the increased refractive index ca uses noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex. Adding barium also increases the refract ive index. Thorium oxide gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its radioacti vity has been replaced by lanthanum oxide in modern eye glasses. Large amounts o f iron are used in glass that absorbs infrared energy, such as heat absorbing fi lters for movie projectors, while cerium(IV) oxide can be used for glass that ab sorbs UV wavelengths. Another common glass ingredient is "cullet" (recycled glass). The recycled glass saves on raw materials and energy. However, impurities in the cullet can lead t o product and equipment failure. Finally, fining agents such as sodium sulfate, sodium chloride, or antimony oxid e are added to reduce the bubble content in the glass.[8] Glass batch calculatio n is the method by which the correct raw material mixture is determined to achie ve the desired glass composition. [edit] Composition and properties There are three classes of components for oxide glasses: network formers, interm ediates, and modifiers. The network formers (silicon, boron, germanium) form a h ighly crosslinked network of chemical bonds. The intermediates (titanium, alumin ium, zirconium, beryllium, magnesium, zinc) can act as both network formers and modifiers, according to the glass composition. The modifiers (calcium, lead, lit hium, sodium, potassium) alter the network structure; they are usually present a s ions, compensated by nearby non-bridging oxygen atoms, bound by one covalent b ond to the glass network and holding one negative charge to compensate for the p ositive ion nearby. Some elements can play multiple roles; e.g. lead can act bot h as a network former (Pb4+ replacing Si4+), or as a modifier. The presence of non-bridging oxygens lowers the relative number of strong bonds in the material and disrupts the network, decreasing the viscosity of the melt a nd lowering the melting temperature. The alkaline metal ions are small and mobile; their presence in glass allows a d egree of electrical conductivity, especially in molten state or at high temperat ure. Their mobility however decreases the chemical resistance of the glass, allo wing leaching by water and facilitating corrosion. Alkaline earth ions, with the ir two positive charges and requirement for two non-bridging oxygen ions to comp

ensate for their charge, are much less mobile themselves and also hinder diffusi on of other ions, especially the alkalis. The most common commercial glasses con tain both alkali and alkaline earth ions (usually sodium and calcium), for easie r processing and satisfying corrosion resistance.[9] Corrosion resistance of gla ss can be achieved by dealkalization, removal of the alkali ions from the glass surface by reaction with e.g. sulfur or fluorine compounds. Presence of alkaline metal ions has also detrimental effect to the loss tangent of the glass, and to its electrical resistance; glasses for electronics (sealing, vacuum tubes, lamp s...) have to take this in account. Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, a nd increases refractive index. Lead oxide also facilitates solubility of other m etal oxides and therefore is used in colored glasses. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda g lasses); this allows easier removal of bubbles and working at lower temperatures , hence its frequent use as an additive in vitreous enamels and glass solders. T he high ionic radius of the Pb2+ ion renders it highly immobile in the matrix an d hinders the movement of other ions; lead glasses therefore have high electrica l resistance, about two orders of magnitude higher than soda-lime glass (108.5 v s 106.5 Ohm·cm, DC at 250 °C). For more details, see lead glass.[10] Addition of fluorine lowers the dielectric constant of glass. Fluorine is highly electronegative and attracts the electrons in the lattice, lowering the polariz ability of the material. Such silicon dioxide-fluoride is used in manufacture of integrated circuits as an insulator. High levels of fluorine doping lead to for mation of volatile SiF2O and such glass is then thermally unstable. Stable layer s were achieed with dielectric constant down to about 3.5 3.7.[11] [edit] Contemporary glass production Following the glass batch preparation and mixing, the raw materials are transpor ted to the furnace. Soda-lime glass for mass production is melted in gas fired u nits. Smaller scale furnaces for specialty glasses include electric melters, pot furnaces, and day tanks.[8] After melting, homogenization and refining (removal of bubbles), the glass is fo rmed. Flat glass for windows and similar applications is formed by the float gla ss process, developed between 1953 and 1957 by Sir Alastair Pilkington and Kenne th Bickerstaff of the UK's Pilkington Brothers, who created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered unde r the influence of gravity. The top surface of the glass is subjected to nitroge n under pressure to obtain a polished finish.[12] Container glass for common bot tles and jars is formed by blowing and pressing methods. Further glass forming t echniques are summarized in the table Glass forming techniques. Once the desired form is obtained, glass is usually annealed for the removal of stresses. Surface treatments, coatings or lamination may follow to improve the c hemical durability (glass container coatings, glass container internal treatment ), strength (toughened glass, bulletproof glass, windshields), or optical proper ties (insulated glazing, anti-reflective coating). [edit] Glassmaking in the laboratory A vitrification experiment for the study of nuclear waste disposal at Pacific No rthwest National Laboratory. Failed laboratory glass melting test. The striations must be avoided through goo d homogenization.New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materi als for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals are used. Care must be taken that the raw materials have not rea

cted with moisture or other chemicals in the environment (such as alkali oxides and hydroxides, alkaline earth oxides and hydroxides, or boron oxide), or that t he impurities are quantified (loss on ignition).[13] Evaporation losses during g lass melting should be considered during the selection of the raw materials, e.g ., sodium selenite may be preferred over easily evaporating SeO2. Also, more rea dily 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, a nd by crushing and re-melting the first melt. The obtained glass is usually anne aled to prevent breakage during processing.[13][14] In order to make glass from materials with poor glass forming tendencies, novel techniques are used to increase cooling rate, or reduce crystal nucleation trigg ers. Examples of these techniques include aerodynamic levitation (the melt is co oled whilst floating in a gas stream), splat quenching, (the melt is pressed bet ween two metal anvils) and roller quenching (the melt is poured through rollers) . See also: Optical lens design, Fabrication and testing of optical components [edit] Sol-gel science/technology Main article: Sol-gel [edit] Silica-free glasses Besides common silica-based glasses, many other inorganic and organic materials may also form glasses, including plastics (e.g., acrylic glass), amorphous carbo n, metals, carbon dioxide (see below), phosphates, borates, chalcogenides, fluor ides, germanates (glasses based on GeO2), tellurites (glasses based on TeO2), an timonates (glasses based on Sb2O3), arsenates (glasses based on As2O3), titanate s (glasses based on TiO2), tantalates (glasses based on Ta2O5), nitrates, carbon ates and many other substances.[7] Some glasses that do not include silica as a major constituent may have physicochemical properties useful for their application in fibre optics and other speci alized technical applications. These include fluoride glasses (fluorozirconates, fluoroaluminates), aluminosilicates, phosphate glasses, borate glasses, and cha lcogenide glasses. Under extremes of pressure and temperature solids may exhibit large structural a nd physical changes which can lead to polyamorphic phase transitions.[15] In 200 6 Italian scientists created an amorphous phase of carbon dioxide using extreme pressure. The substance was named amorphous carbonia(a-CO2) and exhibits an atom ic structure resembling that of silica.[16] [edit] Physics of glass See also Physics of glass Unsolved problems in physics What is the nature of the transition between a flui d or regular solid and a glassy phase? What are the physical mechanisms giving r ise to the general properties of glasses? The amorphous structure of glassy Silica (SiO2) in two dimensions. No long range order is present, however there is local ordering with respect to the tetrahedr al arrangement of Oxygen (O) atoms around the Silicon (Si) atoms.The standard de finition of a glass (or vitreous solid) is a solid formed by rapid melt quenchin g.[3][4][5][17] If the cooling is sufficiently rapid (relative to the characteri stic crystallization time) then crystallization is prevented and instead the dis ordered atomic configuration of the supercooled liquid is frozen into the solid state at the glass transition temperature Tg. Generally, the structure of a glas s exists in a metastable state with respect to its crystalline form, although in

certain circumstances, for example in atactic polymers, there is no crystalline analogue of the amorphous phase.[18] As in other amorphous solids, the atomic s tructure of a glass lacks any long range translational periodicity. However, due to chemical bonding characteristics glasses do possess a high degree of short-r ange order with respect to local atomic polyhedra.[19] It is deemed that the bon ding structure of glasses, although disordered, has the same symmetry signature (Hausdorff-Besicovitch dimensionality) as for crystalline materials.[20] [edit] Glass versus a supercooled liquid Glass is generally classed as an amorphous solid rather than a liquid.[17][21] G lass displays all the mechanical properties of a solid. The notion that glass fl ows to an appreciable extent over extended periods of time is not supported by e mpirical research or theoretical analysis (see viscosity of amorphous materials) . From a more commonsense point of view, glass should be considered a solid sinc e it is rigid according to everyday experience.[22] Some people consider glass to be a liquid due to its lack of a first-order phase transition[21][23] where certain thermodynamic variables such as volume, entrop y and enthalpy are discontinuous through the glass transition range. However, th e glass transition may be described as analogous to a second-order phase transit ion where the intensive thermodynamic variables such as the thermal expansivity and heat capacity are continuous.[20] Despite this, the equilibrium theory of ph ase transformations in solids does not entirely hold for glass, and hence the gl ass transition cannot be classed as one of the classical equilibrium phase trans formations in solids.[5] Although the atomic structure of glass shares characteristics of the structure i n a supercooled liquid, glass tends to behave as a solid below its glass transit ion temperature.[24] A supercooled liquid behaves as a liquid, but it is below t he freezing point of the material, and will crystallize almost instantly if a cr ystal 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 deg rees of freedom that remain active, whereas rotational and translational motion is arrested. This helps to explain why both crystalline and non-crystalline soli ds exhibit rigidity on most experimental time scales. [edit] 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 ma tter of centuries. It is then assumed that the glass was once uniform, but has f lowed to its new shape, which is a property of liquid.[25] In actuality, the rea son for this 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 an d 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 th e disk became thicker as the glass spun. When actually installed in a window fra me, the glass would be placed thicker side down both for the sake of stability a nd to prevent water accumulating in the lead cames at the bottom of the window.[ 26] Occasionally such glass has been found thinner side down or thicker on eithe r side of the window's edge, as would be caused by carelessness at the time of i nstallation. Mass production of glass window panes in the early twentieth century caused a si milar effect. In glass factories, molten glass was poured onto a large cooling t able and allowed to spread. The resulting glass is thicker at the location of th e pour, located at the center of the large sheet. These sheets were cut into sma ller window panes with nonuniform thickness, typically with the location of the

pour centred in one of the panes (known as "bull's-eyes") for decorative effect. Modern glass intended for windows is produced as float glass and is very unifor m 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. Henc e, the relaxation period (characteristic flow time) of cathedral glasses would b e even longer."[27] (1032 years is many times longer than the estimated age of t he Universe.) If medieval glass has flowed perceptibly, then ancient Roman and Egyptian object s should have flowed proportionately more but this is not observed. Similarly, p rehistoric obsidian blades should have lost their edge; this is not observed eit her (although obsidian may have a different viscosity from window glass).[21] If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes. Any slig ht deformation in the antique telescopic lenses would lead to a dramatic decreas e in optical performance, a phenomenon that is not observed.[21] There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical wi ndow glass. Some glasses have a glass transition temperature close to or below room temperat ure. The behavior of a material that has a glass transition close to room temper ature depends upon the timescale during which the material is manipulated. If th e material is hit it may break like a solid glass, but if the material is left o n a table for a week it may flow like a liquid. This simply means that for the f ast timescale its transition temperature is above room temperature, but for the slow one it is below. The shift in temperature with timescale is not very large however, as indicated by the transition of polypropylene glycol of -72 °C and -71 °C over different timescales.[18] To observe window glass flowing as liquid at roo m temperature we would have to wait a much longer time than any human can exist. Therefore it is safe to consider a glass a solid far enough below its transitio n temperature: Cathedral glass does not flow because its glass transition temper ature is many hundreds of degrees above room temperature. Close to this temperat ure there are interesting time-dependent properties. One of these is known as ag ing. Many polymers that we use in daily life such as polystyrene and polypropyle ne are in a glassy state but they are not too far below their glass transition t emperature as opposed to rubber which is used above its glass transition tempera ture. Their mechanical properties may well change over time and this is serious concern when applying these materials in construction. In general for polymers t here is a relation between the glass transition temperature and the speed of the deformation. [edit] Physical properties See also: List of physical properties of glass [edit] Optical properties Glass is in widespread use largely to the production of glass compositions that are transparent to visible wavelengths of light. In contrast, polycrystalline materials in general do not transmit visible light. [citation needed] The individual crystallites may be transparent, but their face ts (grain boundaries) reflect or scatter light. Light entering a polycrystal is repeatedly scattered until it re-emerges form the surface in random directions. This subsurface scattering mechanism,[28][29] together with scattering by surfac e irregularities, gives rise to diffuse reflection and hence although it does no t absorb light the polycrystal is not transparent. This mechanism, which causes objects to be opaque, is a crucial mechanism for vision, because most objects ar e seen by our eyes through their diffuse reflection.[30]

Glass does not contain the internal subdivisions associated with grain boundarie s in polycrystals and hence does not scatter light in the same manner as a polyc rystalline material.[citation needed] The surface of a glass is often smooth sin ce during glass formation the molecules of the supercooled liquid are not forced to dispose in rigid crystal geometries and can follow surface tension, which im poses a microscopically smooth surface.[citation needed] These properties, which give glass its clearness, can be retained even if glass is partially absorbing (colored, see below).[citation needed] Glass has the ability to refract, reflect and transmit light following geometric al optics, without scattering it, and it is used in the manufacture of lenses an d windows. Common glass has a refraction index around 1.5.[citation needed] Acco rding to Fresnel equations, the reflectivity of a sheet of glass is about 4% per each surface (at normal incidence), and its transmissivity about 92%.[citation needed] [edit] Color Main article: Glass coloring and color marking See also: Transparent_materials#Absorption of light in solids Common soda-lime float glass appears green in thick sections because of Fe2+ imp urities.Many glasses have a chemical composition which includes what are referre d to as absorption centers. This may cause them to be selective in their absorpt ion of visible lightwaves (or white light frequencies). They absorb certain port ions of the visible spectrum, while reflecting others. The frequencies of the sp ectrum which are not absorbed are either reflected back or transmitted for our p hysical observation. This is what gives rise to color. Thus, color in glass may be obtained by addition of electrically charged ions (o r color centers) that are homogeneously distributed, and by precipitation of fin ely dispersed particles (such as in photochromic glasses).[7] Ordinary soda-lime glass appears colorless to the naked eye when it is thin, although iron(II) oxi de (FeO) impurities of up to 0.1 wt%[31] produce a green tint which can be viewe d in thick pieces or with the aid of scientific instruments. Further FeO and Cr2 O3 additions may be used for the production of green bottles. Sulfur, together w ith carbon and iron salts, is used to form iron polysulfides and produce amber g lass ranging from yellowish to almost black.[32] Manganese dioxide can be added in small amounts to remove the green tint given by iron(II) oxide. [edit] Optical waveguides Main article: Waveguide (optics) The propagation of light through a multi-mode optical fiber. A laser bouncing down an acrylic rod, illustrating the total internal reflection of light in a multimode optical fiber.Optically transparent materials focus on the response of a material to incoming light waves of a range of wavelengths. Fr equency selective optical filters can be utilized to alter or enhance the bright ness and contrast of a digital image. Guided light wave transmission via frequen cy selective waveguides involves the emerging field of fiber optics and the abil ity of certain glassy compositions as a transmission medium for a range of frequ encies simultaneously (multimode optical fiber) with little or no interference b etween competing wavelengths or frequencies. This resonant mode of energy and da ta transmission via electromagnetic (light) wave propagation, though low powered , is relatively lossless. An optical fiber is a cylindrical dielectric waveguide that transmits light alon g its axis by the process of total internal reflection. The fiber consists of a core surrounded by a cladding layer. To confine the optical signal in the core, the refractive index of the core must be greater than that of the cladding. The

index of refraction is a way of measuring the speed of light in a material. (Not e: The index of refraction is the ratio of the speed of light in a vacuum to the speed of light in a given medium. (The index of refraction of a vacuum is there fore equal to 1, by definition). The larger the index of refraction, the more sl owly light travels in that medium. Typical values for core and cladding of an op tical fiber are 1.48 and 1.46, respectively. When light traveling in a dense medium hits a boundary at a steep angle, the lig ht will be completely reflected. This effect is used in optical fibers to confin e light in the core. Light travels along the fiber bouncing back and forth off o f the boundary. Because the light must strike the boundary with an angle greater than the critical angle, only light that enters the fiber within a certain rang e of angles will be propagated. This range of angles is called the acceptance co ne of the fiber. The size of this acceptance cone is a function of the refractiv e index difference between the fiber's core and cladding. Optical waveguides are used as components in integrated optical circuits (e.g. l ight-emitting diodes, LEDs) or as the transmission medium in local and long haul optical communication systems. Also of value to materials science is the sensit ivity of materials to thermal radiation in the infrared (IR) portion of the EM s pectrum. This infrared homing (or "heat-seeking") capability is responsible for such diverse optical phenomena as "night vision" and IR luminescence. [edit] Modern glass art Main article: Studio glass A vase being created at the Reijmyre glassworks, Sweden Paperweight with items inside the glass, Corning Museum of Glass A glass sculpture by Dale Chihuly, The Sun at the Gardens of Glass exhibition in Kew Gardens, London. The piece is 13 feet (4 metres) high and made from 1000 separa te glass objects. Glass tiles mosaic (detail).From the 19th century, various types of fancy glass started to become significant branches of the decorative arts. Cameo glass was r evived for the first time since the Romans, initially mostly used for pieces in a neo-classical style. The Art Nouveau movement in particular made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy important names in the first French wave of the movement, producing colored vases and similar pieces, often i n cameo glass, and also using lustre techniques. Louis Comfort Tiffany in Americ a specialized in secular stained glass, mostly of plant subjects, both in panels and his famous lamps. From the 20th century, some glass artists began to class themselves as in effect sculptors working in glass, and as part of the fine arts . 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 diam ond saw, or copper wheels embedded with abrasives, and polished to give gleaming facets; the technique used in creating Waterford crystal.[33] Art is sometimes etched into glass via the use of acid, caustic, or abrasive substances. Traditio nally this was done after the glass was blown or cast. In the 1920s a new mouldetch process was invented, in which art was etched directly into the mould, so t hat 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 o f colored glass, led to cheap glassware in the 1930s, which later became known a s Depression glass.[34] 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 oft en used, though sometimes the glass is painted, innumerable examples exist of th e use of stained glass. [edit] Museums Apart from historical collections in general museums, modern works of art in gla ss can be seen in a variety of museums, including the Chrysler Museum, the Museu m 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 co llection of glass art and history, with more than 45,000 objects in its collecti on.[35] The Harvard Museum of Natural History has a collection of extremely detailed mod els 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 Bla schka Glass Flowers are still an inspiration to glassblowers today.[36] [edit] See also Aluminium oxynitride Ceramic engineering Colloidal crystal Fiberglass Fulgurite Glass transition Glass recycling Glazier History of glass Nanomaterials Optical fiber Magnifying glass Superglass Transparent materials Tektite Volcanic glass Vitrification Vitrified sand Devitrification [edit] References 1.^ Douglas, R. W. (1972). A history of glassmaking. Henley-on-Thames: G T Fouli s & Co Ltd. ISBN 0854291172. 2.^ ASTM definition of glass from 1945; also: DIN 1259, Glas Begriffe für Glasarte n und Glasgruppen, September 1986 3.^ a b Zallen, R. (1983). The Physics of Amorphous Solids. New York: John Wiley . ISBN 0471019682. 4.^ a b Cusack, N. E. (1987). The physics of structurally disordered matter: an introduction. Adam Hilger in association with the University of Sussex press. IS BN 0852748299. 5.^ a b c Elliot, S. R. (1984). Physics of Amorphous Materials. Longman group lt d. 6.^ Horst Scholze (1991). Glass Nature, Structure, and Properties. Springer. ISB N 0-387-97396-6. 7.^ a b c d Werner Vogel (1994). Glass Chemistry (2 ed.). Springer-Verlag Berlin and Heidelberg GmbH & Co. K. ISBN 3540575723. 8.^ a b c B. H. W. S. de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol. A12, VCH Publishers, Weinheim, Germany, 1989, ISB N 3-527-20112-5, pp. 365 432. 9.^ Eric Le Bourhis (2007). Glass: Mechanics and Technology. Wiley-VCH. p. 74. I SBN 3527315497. ass%22&cd=1#v=onepage&q=%22borate%20glass%22. 10.^ James F. Shackelford, Robert H. Doremus (2008). Ceramic and Glass Materials

: Structure, Properties and Processing. Springer. p. 158. ISBN 0387733612. http: // ge&q=%22glass%20solders%22. 11.^ Robert Doering, Yoshio Nishi (2007). Handbook of semiconductor manufacturin g technology. CRC Press. pp. 12 3. ISBN 1574446754. VVKz_hjBgC&pg=SA12-PA3&dq=semiconductor+failure+microphotograph&cd=5#v=onepage&q =. 12.^ "PFG Glass". Retrieved 2 009-10-24. 13.^ a b "Glass melting, Pacific Northwest National Laboratory". Depts.washingto Retrieved 2009-10-24. 14.^ Alexander Fluegel. "Glass melting in the laboratory". Retrieved 2009-10-24. 15.^ P. F. McMillan (2004). "Polyamorphic transformations in liquids and glasses ". Journal of Materials Chemistry 14: 1506 1512. doi:10.1039/b401308p. 16.^ carbon dioxide glass created in the lab 15 June 2006, www.newscientisttech. com. Retrieved 3 August 2006. 17.^ a b S. A. Baeurle et al. (2006). "On the glassy state of multiphase and pur e polymer materials". Polymer 47: 6243 6253&year=2006. doi:10.1016/j.polymer.2006. 05.076. 18.^ a b Folmer, J. C. W.; Franzen, Stefan (2003). "Study of polymer glasses by modulated differential scanning calorimetry in the undergraduate physical chemis try laboratory". Journal of Chemical Education 80 (7): 813. doi:10.1021/ed080p81 3. 19.^ P.S. Salmon (2002). "Order within disorder". Nature Materials 1 (2): 87. do i:10.1038/nmat737. PMID 12618817. 20.^ a b M.I. Ojovan, W.E. Lee (2006). "Topologically disordered systems at the glass transition". J. Phys.: Condensed Matter 18: 11507 11520. doi:10.1088/0953-89 84/18/50/007. 21.^ a b c d Philip Gibbs. "Is glass liquid or solid?". /baez/physics/General/Glass/glass.html. Retrieved 2007-03-21. 22.^ "Philip Gibbs" Glass Worldwide, (May/June 2007), pp. 14 18 23.^ Jim Loy. "Glass Is A Liquid?". Ret rieved 2007-03-21. 24.^ Florin Neumann. "Glass: Liquid or Solid Science vs. an Urban Legend". http: // Re trieved 2007-04-08. 25.^ Chang, Kenneth (2008-07-29). "The Nature of Glass Remains Anything but Clea r". New York Times. 75070400&en=048ade4011756b24&ei=5124&partner=permalink&exprod=permalink. Retriev ed 2008-07-29. 26.^ "Dr Karl's Homework: Glass Flows". 2000-01-26. Retrieved 2009-10-24. 27.^ Zanotto, Edgar Dutra (1998). "Do Cathedral Glasses Flow?". American Journal of Physics 66: 392 396. doi:10.1119/1.19026. 28.^ P.Hanrahan and W.Krueger (1993), Reflection from layered surfaces due to su bsurface scattering. In SIGGRAPH 93 Proceedings, J. T. Kajiya, Ed., vol. 27, pp. 165 174. 29.^ H.W.Jensen et al. (2001), A practical model for subsurface light transport. In 'Proceedings of ACM SIGGRAPH 2001', pp. 511 518 30.^ Kerker, M. (1909). The Scattering of Light. New York: Academic. 31.^ "High temperature glass melt property database for process modeling"; Eds.: Thomas P. Seward III and Terese Vascott; The American Ceramic Society, Westervi lle, Ohio, 2005, ISBN 1-57498-225-7 32.^ Substances Used in the Making of Coloured Glass (David M I ssitt). Retrieved 3 August 2006. 33.^ "Waterford Crystal Visitors Centre". . Retrieved 2007-10-19. 34.^ "Depression Glass". Retrie

ved 2007-10-19. 35.^ "Corning Museum of Glass". Retri eved 2007-10-14. 36.^ the Harvard Museum of Natural History's page on the exhibit[dead link] [edit] Bibliography 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 Examinati on. Oxbow Books, 2004. ISBN 1-84217-104-6 Ghosh, Amalananda (1990). An Encyclopaedia of Indian Archaeology. BRILL. ISBN 90 04092625. Gowlett, J.A.J. (1997). High Definition Archaeology: Threads Through the Past. R outledge. ISBN 0415184290. Noel C. Stokes; The Glass and Glazing Handbook; Standards Australia; SAA HB125 199 8 Stookey, D.Donald. Explorations in Glass: An Autobiography. Wiley, 2000. ISBN 97 8-1-57498-124-7 Vogel, Werner. Chemistry of Glass. Wiley, 1985. ISBN 978-0-916094-73-7 [edit] External links Wikimedia Commons has media related to: Glass Wikisource has the text of the 1911 Encyclopædia Britannica article Glass. Glass Encyclopedia A comprehensive guide to all types of antique and collectable glass, with information, pictures and references The Canadian Museum of Civilization The Story of Glass Making in Canada Corning Museum of Glass [show]v d eGlass science topics Basics Glass definition · Is glass a liquid or a solid? · Glass-liquid transition · Ph ysics of glass · Supercooling Glass formulation AgInSbTe · Bioglass · Borophosphosilicate glass · Borosilicate glass · Ceramic glaze · Chalcogenide glass · Cobalt glass · Cranberry glass · Crown glass · Flint glass · Fluorosilicate glass · Fused quartz · GeSbTe · Gold ruby glass · Lead glass · Milk glass · Phosphosilicate glass · Photochromic lens glass · Silicate glass · Soda-lime gla ss · Sodium hexametaphosphate · Soluble glass · Ultra low expansion glass · Uranium glas s · Vitreous enamel · Wood's glass · ZBLAN Glass-ceramics Bioactive glass · CorningWare · Glass-ceramic-to-metal seals · Macor · Ze rodur Glass preparation Annealing · Chemical vapor deposition · Glass batch calculation · Gl ass forming · Glass melting · Glass modeling · Ion implantation · Liquidus temperature · S ol-gel technique · Viscosity Optics Achromat · Dispersion · Gradient index optics · Hydrogen darkening · Optical ampl ifier · Optical fiber · Optical lens design · Photochromic lens · Photosensitive glass · R efraction · Transparent materials Surface modification Anti-reflective coating · Chemically strengthened glass · Corro sion · Dealkalization · DNA microarray · Hydrogen darkening · Insulated glazing · Porous g lass · Self-cleaning glass · Sol-gel technique · Toughened glass Diverse topics Diffusion · Glass-coated wire · Glass databases · Glass electrode · Glass fiber reinforced concrete · Glass history · Glass ionomer cement · Glass microspheres

· Glass-reinforced plastic · Glass science institutes · Glass-to-metal seal · Porous gl ass · Prince Rupert's Drops · Radioactive waste vitrification · Windshield [show]v d eGlass forming techniques

Commercial techniques Float glass process · Blowing and pressing (containers) · Extr usion / Drawing (fibers, glasswool) · Drawing (optical fibers) · Precision glass mou lding · Overflow downdraw method · Pressing · Casting · Cutting · Flame polishing · Chemical polishing · Diamond turning · Rolling Artistic and historic techniques Beadmaking · Blowing · Blown plate · Broad sheet · Cane working · Crown glass · Cylinder blown sheet · Engraving · Etching · Fourcault process · Fu sing · Lampworking · Machine drawn cylinder sheet · Millefiori · Polished plate · Slumping · Stained glass fusing · Stained glass production See also Glossary of glass art terms [show]v d eGlass makers and brands

Contemporary companies Anchor Hocking · Arc International · Ardagh · Armashield · Asahi · Aurora Glass Foundry · Baccarat · Blenko Glass Company · Bodum · Corning · Dartington Crystal · Daum · Edi burgh Crystal · Fanavid · Fenton Art Glass Company · Firozabad glass industry · Franz Ma yer · Glava · Glaverbel · Hardman & Co. · Heaton, Butler and Bayne · Holmegaard Glassworks · Holophane · Hoya · Kingdom of Crystal · Kokomo Opalescent Glass Works · Kosta Glasbruk · Libbey Owens Ford · Liuli Gongfang · Iittala · Luoyang · Johns Manville · Mats Jonasson Måle rås · Moser Glass · Mosser Glass · Nippon Sheet Glass · Ohara · Orrefors Glasbruk · Osram · O s Corning · Owens-Illinois · Pauly & C. - Compagnia Venezia Murano · Phu Phong · Pilking ton · PPG · Preciosa · Quinn Group · Riedel · Royal Leerdam Crystal · Saint-Gobain · Samsung orning Precision Glass · Schonbek · Schott · Shrigley and Hunt · Steuben Glass · Sterlite Optical Technologies · Swarovski · Tyrone Crystal · Val Saint Lambert · Verrerie of Breh at · Waterford · Watts & Co · World Kitchen · Xinyi Glass · Zwiesel Historic companies Bakewell Glass · Belmont Glass Company · Boston and Sandwich Glass Company · Carr Lowrey Glass Company · Cambridge Glass · Chance Brothers · Clayton and Bell · Dunb ar Glass · Fostoria Glass Company · General Glass Industries · Alexander Gibbs · Grönvik g lasbruk · Hazel-Atlas · Heisey · Hemingray Glass Company · Knox Glass Bottle Company · Lav ers, Barraud and Westlake · Manufacture royale de glaces de miroirs · Morris & Co. · O ld Dominion Glass Company · James Powell and Sons · Ravenhead glass · The Root Glass C ompany · Sneath Glass Company · Ward and Hughes · Westmoreland Glass Company · Whitall T atum Company · White Glass Company · Worshipful Company

Glassmakers John Adams · Richard M. Atwater · Frederick Carder · Irving Wightman Colbu rn · Henry Crimmel · Henry Clay Fry · Friedrich · A. H. Heisey · Libbey · Antonio Neri · Alas air Pilkington · Salviati · Otto Schott · S. Donald Stookey · W. E. S. Turner · John M. Wh itall

Trademarks and brands Bohemian glass · Bomex · Burmese glass · Chevron bead · Corelle · CorningWare · C ranberry glass · Cristallo · Duran · Endural · Favrile · Fire King · Gold Ruby · MACOR · Mura glass · Opaline glass · Pyrex · Ravenhead glass · Tiffany glass · Vitrite · Vitrolite · Vycor Waterford Crystal · Wood's glass · Zerodur

Retrieved from "" Categories: Glass | Dielectrics | Packaging materials | Recyclable materials | S culpture materials Hidden categories: All articles with dead external links | Articles with dead ex ternal links from October 2009 | Wikipedia indefinitely move-protected pages | A ll articles with unsourced statements | Articles with unsourced statements from July 2010

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