:For eyeglasses, see spectaclesThe physics definition of a glass is a uniform amorphous solid material, usually produced when a suitably viscous molten material cools very rapidly, thereby not giving enough time for a regular crystal lattice to form. The remainder of this article will be concerned with a specific type of glass -- the silica based glasses in common use as a building, container or decorative material.
In its pure form, glass is a transparent, relatively strong, hard-wearing, essentially inert, and biologically inactive material which can be formed with very smooth and impervious surfaces. These desirable properties lead to a great many uses of glass . Glass is, however, brittle and will break into sharp shards. These properties can be modified, or even changed entirely, with the addition of other compounds or heat treatment.
Glass can be made transparent and flat, or into other shapes and colors as shown in this ball from the Verrerie of Brehat in Brittany.
Common glass is mostly amorphous silicon dioxide ( Si O }), which is the same chemical compound found in quartz, or in its polycrystalline form, sand. Pure silica has a melting point of about 2000 °C (3632 °FThis article is about the temperature scale; see also Fahrenheit graphics API. Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit ( 1686 1736), who proposed it in 1724. In this scale, the freezing point of water is 32 de), so two other substances are always added to the sand in the glass-making process. One is soda ( sodium carbonateProperties General Name Sodium carbonate Chemical formula Na CO Appearance White solid Physical Formula weight 106. 0 amu Melting point 1124 K (851 °C) Boiling point Decomposes at ? Density 2. 5 ×103 kg/ m3 Crystal structure ? Solubility 10. 9 g in 100g w Na } C O }), or potashPotash is the common name of potassium hydroxide ( K OH), a substance that has been used since antiquity in the manufacture of glass and soap, and as a fertilizer. The name comes from the English words pot and ash referring to its discovery in the water-, the equivalent potassiumPotassium carbonate (also known as pearl ash or salts of tartar is a white salt soluble in water which forms a strongly alkaline solution. Properties General Name Potassium carbonate Chemical formula K CO Appearance White solid Physical Formula weight 138 compound, which lowers the melting point to about 1000 °C. However, the soda makes the glass water-soluble, which is obviously undesirable, so lime ( calcium oxideProperties General Name Calcium oxide Chemical formula Ca O Appearance White solid Physical Formula weight 56. 1 amu Melting point 3200 K (2927 °C) Boiling point 3773 K (3500 °C) Density 3. 3 ×103 kg/ m3 Crystal structure NaCl Solubility hydrolysed Thermo, Ca O) is the third component, added to restore insolubility.
The word glass, comes from LatinAlternative meanings: See Latin (disambiguation Latin was the language originally spoken in the region around Rome called Latium. It gained great importance as the formal language of the Roman Empire. All Romance languages are descended from Latin, and ma glacies (ice) GermanGerman (called Deutsch in German in which germanisch refers to prechristian times), is a member of the western group of Germanic languages and one of the world's major languages. It is the language with the most native speakers in the European Union. Glas, M.E. glas, A.S. glaes. Germanic tribes used the word glaes to describe amberThis is about the material called amber. For other things called amber, see Amber (disambiguation). Amber is a fossil resin much used for the manufacture of ornamental objects. Although not mineralized it is sometimes considered and used as a gemstone., recorded by Roman historians as glaesum. Anglo-Saxons used the word glaer for amber.
