Origins of glass and crystal

Glass is a non-thermoplastic polymer families are all inorganic materials, the structure is an inorganic, may be formed at above 650oc After cooling a transparent, corrosion, wear, compression and other characteristics. Lower than the thermal expansion coefficient of the glass steel is a poor conductor of electricity and heat, is a living brittle amorphous material. Specific gravity: 2.46 to 2.5 linear expansion coefficient: 9 ~ 10x10-6/oc (~ 350oc) Specific heat: 0.2 (0o ~ 50oc), practical surface tensile strength: 500kgf/cm2 glass call originated in the Tang Dynasty, referring to the glass material plus referred to in the lead oxide crystal glass. When the proportion of added lead oxide, with the customary definition of different countries have, in general, the ratio of lead oxide than 24%, the refractive index of the glass transmittance are good, but also heavier and soft, very suitable for firing into exquisite glass art. When General European countries mentioned crystal ware, meaning the use of such crystal glass material, which is generally more expensive than glass can match. Artificial glass "glass" is the glass, just added a lead becomes very crystal clear before anyone called Crystal. Terms of pure artistic vision to appreciate, of course, also the value of the collection. If participants natural crystal glass energy or natural growth is the difference between a great time. This is sure to know. Like Austria or Italy, the high-priced bottles of crystal cup glass dish or crystal glass ornaments with a variety of cute little animals, lotus crystal glass used in Buddhism, crystal chandeliers, crystal glass almost all! There is no magnetic energy. In fact, crystal glass imitation of natural crystal glass manufacture, it is often heard lead glass, lead glass was added to increase the refractive index of the glass, so as to reduce the hardness is easily refined; generally sell pretty crystal cup also lead glass.