Crystal Glass Connotation And Extension

According to the American ASTM C162-89, crystal glass is defined as a colorless glass with high transparency and often used in the manufacture of art or tableware. According to this definition, the scope is very broad, including Venetian soda-lime crystal (Cristallo), Bohemia's potassium-lime crystal and potassium-sodium-lime crystal glass (Crystalex) and lead crystals. But few people regard the Venetian crystallo as crystal glass, which has basically become a historical term.

The European Community (EEC) issued guidelines in the form of document 312/1972 in 1972, stipulating that lead crystal glass is divided into:

(1) Full lead crystal (Full lead crystal) contains PbO≥30%, density d≥3.0g/cm3, refractive index nD≥1.545;

(2) Lead crystal contains PbO≥24%;

(3) Crystal glass does not specify the content of PbO, but it is pointed out that the German market for glass containing 18% PbO and d≥2.7 can be called PRESSB LEL KRISTALL or BLEIKRISTALL GEPRESST.

Variety

Although the EEC 312/1972 document has been published for more than 30 years, it is still being implemented. This document clarifies the area of lead crystal and crystal glass, and full lead crystal and lead crystal without glass. Some European countries have modified and supplemented this document,

like

European Nine Countries Standard

BHSL 326 is similar to the EEC 312/1972 guidance document. Divided into:

(1) High-lead crystal PbO≥30%, refractive index nD≥1.56;

(2) Lead crystal PbO≥24%, refractive index nD≥1.545.

U.K

The crystal glass specification in BS 3828-73 is supplemented as follows:

(1) All-lead crystals containing PbO≥30%, density d≥3.0g/cm3, refractive index nD≥1.560;

(2) Lead crystal containing PbO≥24%; density d≥2.90g/cm3, refractive index nD≥1.545;

(3) Crystal glass ZnO, BaO, PbO, K2O in single component or total component ≥10%, density d≥2.45g/cm3, refractive index nD≥1.52;

(4) Single component or total component of BaO, PbO, K2O ≥10%, density ≥2.4 g/cm3.

France

NF B 30-004 also divides lead crystal glass into:

(1) 30% high crystal glass containing PbO≥30%, density d≥3.0g/cm3, refractive index nD≥1.560;

(2) 24% crystal glass contains PbO≥24%, density d≥2.90g/cm3, refractive index nD≥1.545.

Austria

The crystal glass is divided into:

(1) Full Crystal PbO≥24%;

(2) Crystal PbO 10%~24%;

(3) Fine Crystal PbO6%~10%.

Czech Republic

Then the lead crystal glass is divided into:

(1) All lead crystal glass PbO≥30%;

(2) Lead crystal glass PbO≥24%;

(3) Low-lead crystal glass PbO≥7%.

China

There is no national and industry standard yet, and the custom is divided into:

(1) High-lead crystal glass PbO≥30%;

(2) Lead crystal glass PbO≥24%

Poland

The Polish Art Center defines lead crystal as containing 24%~33% PbO. In the EU Lead Crystal website, lead crystal refers to PbO of 10%-28%, density ≮2.45g/cm3, refractive index nD≮1.520.

In Europe, there is often no strict distinction between full-lead and medium-lead crystals. Glass containing PbO24%~30% can be called full-lead crystal, such as

Swarovski contains PbO 32% called full lead crystal,

Watford 30% PbO is called full lead crystal,

Baccarat and Bohemian full lead crystal refer to glass containing 24% PbO.

However, when Chinese glass is exported, the contract strictly requires that the lead content is 24% PbO, and the total lead content is PbO ≥ 30%. The customs needs to conduct analysis and testing. In order to meet this requirement, when designing the glass composition, it is necessary to consider the lead content in the manufacturing process. For the volatilization problem, the general lead composition design contains 25% PbO, and the full lead (high lead) design composition contains 33% PbO.

In the 1950s, Eastern European countries such as the former Soviet Union and the Czech Republic developed lead-free crystal glass. By the end of the last century, in order to prevent pollution, lead-free crystal glass attracted more attention. , Developed into multi-element crystal glass such as zirconium crystal, lead-free crystal glass includes:

(1) Barium crystal glass;

(2) Zinc crystal glass;

(3) Titanium crystal glass;

(4) Zirconium crystal glass;

(5) Mixed crystal glass.

Lead crystal glass has a high refractive index, high dispersion, high density, and a heavy texture. There is a metal sound when it is struck, and the remaining sound surrounds the beam. It is beautiful and pleasant. It is used as a wine utensil and will produce good results when clinking glasses. In the 18th century, the saint head horse tulip goblet designed by Harcourt became a typical shape. Later, different cup shapes were designed for different varieties of famous wines. Crystal chandeliers and various lightings have almost become indispensable luxury lamps for churches, conference venues, hotels, and high-end residences. Watford made large chandeliers for famous buildings in Windsor Castle, Westminster Cathedral, and Kennedy Center. The building adds luster and luster. The variety of crystals has developed from wine utensils, drinking utensils, tableware, lamps, prizes (trophies), paperweights, to imitation jewelry, jewelry, fashion, shoes, hats, clocks and watches, as well as furniture, building components, etc.; from a few nanometers of reflective micro Beads, rice beads of a few millimeters, glass buildings and outdoor sculptures of tens of meters; everything from utensils for daily use, decorations, displays, works of art to high-tech products. Waterford, Baccarat, and Swarovski crystals have almost become symbols of the status of celebrities and rich people.

Every New Year’s Eve party held in Times Square, New York, there is a crystal ball with a diameter of 1.829m (6 feet) and a weight of 485.98kg (1070 pounds) made by Watford, England. It contains 600 high-brightness halogen lamps and 60 halogen flashing lights hung outside the high-rise buildings, slowly descending with the cheers of the crowd, symbolizing the beginning of a new year.

Cutting glass is a special product of lead crystal. It makes full use of high lead crystal with high refractive index (nD>1.57), large dispersion (0.0235), and high transparency (the visible light absorption rate of 1cm thick lead crystal does not exceed 0.5%~ 1%) and other characteristics, cutting, grinding, polishing into diamond-like corners and corners, light can be reflected from many corners, and at the same time can also be refracted from the corners, these corners also act as prisms, and partially decompose white light into Seven-color iridescent, showing magnificent brilliance. The engraved crystal ball has 224 engraved faces, and the most recently engraved lead crystal sports competition prize has as many as 520 engraved faces (edges). The most famous engraved lead crystals in the world are Swarovski in Austria, Waterford in Ireland, Baccart in France, and Webb Corbett in England. These are all famous Companies that engrave and polish lead crystal products.