Color, in glass

Thus, most of the color in glass is produced by metallic ions derived from minerals, usually in relatively small amounts within the glass structure. Already in antiquity there was awareness of the effects of some other metals on the color of glass. It was known then, for example, that even relatively small amounts of specific metals, included as minerals in the components of a glass melt, could produce colored glass particular metalliferous minerals were therefore added to glass melts so as to produce special and... 

Solarization is a photochemical reaction which leads to a change in color in glass. It is the result of long term exposure to the ultra violet radiation from sunlight. When certain multivalent ions or combinations of ions are present, their valence can be changed by the ionizing radiation. 

Cadmium nitrate is the preferred starting material for Cd(OH)2 for use as the anode in alkaline batteries. The sintered anode matrix of such batteries is saturated with cadmium nitrate (480—500 g/L Cd) and cadmium hydroxide is formed therein by standardized electrolysis and drying (37). The tetrahydrate sells for 29.10/kg in 20 kg lots. Other uses include photographic emulsions and as a colorant in glass and ceramics. 

Selenium is also used to impart a ruby-red color to glass, and to neutralize the green color in glass which is due to the presence of iron. 

Use Plant nutrient colorant in glass, glazes, enamels analytical chemistry. 

Use Mordant, catalyst, aniline black preparation, reducing agent, colorant in glasses and ceramics. 

Selenium is quite rare (9 X 10 % of the earth s crust). It occurs mainly as an impurity in sulfur, sulfide, and sulfate deposits. It is obtained from the flue dusts that result from roasting sulfide ores and from the anode mud formed in the electrolytic refining of copper. It is used as a red coloring in glass. The gray crystalline allotropic form of selenium has an electrical conductivity that is very light-sensitive, so it is used in photocopy machines and in solar cells. 

Colored Glass Thorium-230 can be used to provide coloring in glass objects. One method of producing thorium-230 is through the radioactive decay of actinium-230. Is this an example of alpha decay or beta decay How do you know ... 

Selenium has been found to be the most favorable element for introducing a pink color in glass products. It is a complex process, fraught with diKI culties, but, when successful, delivers to the glass a distribution of spherical particles that absorb light that is not pink. 

Selenium has been found to be the most favorable element for introducing a pink color in glass products. (Laumerle Dreamstime.com)... 

Deny coloring matter of emerald due to organic matter and heated to prove. Imitate color in glass by a small amount of chromium. 

Absorption in the visible is perceived as color. A number of mechanisms exist for the creation of color in glasses. The most important commercial colored glasses contain either 3d transition metal ions or 4f rare earth (lanthanide) ions, where the coloration arises from the so-called ligand field effect. Other sources of color include the formation of metal or semi-conductor colloidal particles, optical defects induced by solarization or radiation, and charge transfer bands in the visible region of the spectrum. 

Color is produced in ways similar to other glass. (We discussed color in glass in Section 21.8.) As recently as 1999, the French Consumer Safety Committee considered the safety of the use of UO2 dye to make enamels for the preparation of jewelry and enameled tiles. Old yellow enamels contained up to 9% UO2 and frits using nonde-pleted U are certainly more radioactive than those of today. The committee noted that having 50% Pb in the frit might help absorb the radiation, but this increased the toxicity of the frit powder Safety in enameling is therefore always a concern because the technique uses powders. 

F centers in crystals in Section 11.9, and the origins of color in glass in Section 21.8 we will discuss color more in Chapter 36. 

Properties Violet to dark red cryst. insol. in water sol. in common acids m.w. 171.94 Uses Plant nutrient colorant in glass, glazes, enamels analytical chemistry Manuf./Distrib. Shepherd http //www.shepchem. com... 

Iron oxide Iron oxide causes coloration in glass depending on its oxidation state. Iron(II) causes a bluish-green coloration, iron(III) a yellowish coloration. For determination of total iron expressed as Fc203, a UV-visible spectrophotometric method based on 1,10-phenanthroline is used. Hydroxyl-amine is used to ensure all the iron is present as iron(n). 

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