Metallic colorants

This information is given as a summary, and safer or at least less-controversial alternatives to some of the pigments above do exist (though they can be expensive) [1-1, 9-1, 9-4, 9-5]. 

Organic pigments are typically stronger and less opaque than inorganic pigments, but are not as light- or heat-stable. They have smaller particle sizes 

Color Type Chemical Base Common Pigment Designations Application Notes 

White Inorganic Titanium dioxide White 6 Most common pigment, in rutile form some UV absorption 

White Inorganic Zinc sulfide White 7 Brighter, bluer whites nonabrasive to glass fibers 

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Potassium cyanide is primarily used for fine silver plating but is also used for dyes and specialty products (see Electroplating). Electrolytic refining of platinum is carried out in fused potassium cyanide baths, in which a separation from silver is effected. Potassium cyanide is also a component of the electrolyte for the analytical separation of gold, silver, and copper from platinum. It is used with sodium cyanide for nitriding steel and also in mixtures for metal coloring by chemical or electrolytic processes. 

Layer-type dezincification is easy to recognize visually. The original component shape and dimensions are usually preserved, but the metal color changes from the golden yellow of zinc brass to the red of ele-... 

Schilf-glascrz, n. freieslebenite. -rohr, n. reed. Schiller, m. play of colors, iridescence surface color, metallic color, schiller. -farbe, /. changeable color schiller color, surface color, metallic color. 

Chemical conversion coatings are applied to previously deposited metal or basis material for increased corrosion protection, lubricity, preparation of the surface for additional coatings, or formulation of a special surface appearance. This operation includes chromating, phosphating, metal coloring, and passivating. 

Azo dyes and azo pigments are the most important class of both non-metallized and metallized colorants. Therefore, this section is devoted entirely to metal complex azo dyes and pigments. 

Metallic appearance in massive form, black to metallic color in powdered state or in electrodeposited form hexagonal crystal system density 20.53 g/cm3 hardness (Brinell) 250 melts at 3,180°C vaporizes at 5,627°C (estimated) vapor pressure 4.6x10- torr at 2,500°C electrical resistivity 19.14 microhm -cm modulus of elasticity 67x10 psi at 20°C specific magnetic susceptibility 0.369x10 thermal neutron absorption cross section 86 barns/atom superconductivity transition temperature 1.7°K insoluble in water and hydrochloric acid soluble in dilute nitric acid and hydrogen peroxide slightly soluble in sulfuric acid. 

For Zn-Mg alloys in ZnBr2-EMIB-ethylene glycol melts [186] and ZnBr2-EMIB-glycerin containing Mg(II) [187], the grayish metallic colored electrodeposits were obtained. The Mg content in Zn-Mg electrodeposits varied from 12 to 25 mol % [187]. 

Amalgam is aesthetically unattractive compared to new materials. It has a metallic color that does not reproduce the natural appearance of the ce-ramo-organic tooth structure. The release of metallic ions from the amalgam restoration also can discolor the neighboring tooth structure [19]. 

The efficiency of the reflection process depends on the frequency of the incident light, V. For example, as shown in Figure 6.84, silver is highly reflective over the entire visible range. As a result, it has a white metallic color and a bright luster. ... 

A) Interference colors B) Combination pigments Q Metallic colors... 

A naturally occurring alloy of silver with mercuiy, also referred to as mercurian silver, silver amalgam, and argental mercuiy. The natural amalgam crystallizes in the isometric system hardness. 3-3.5 sp gr, 13.75-14.1 luster, metallic, color, silver-white streak, silver-white opaque, Amalgam is found in Bavaria. British Columbia. Chile, the Czech Republic and Slovakia, France, Norway, and Spain. In some areas, it is found in the oxidation zone of silver deposits and as scattered grains in cinnabar ores. 

BOURNONITE. An antimony-copper-lead sulfide corresponding to the formula PbCuSbS3. It is orthorhombic, and repeated twinning often produces crosses or wheel-shaped crystals. It is brittle fracture, subconchoidal hardness, 2.5-3 specific gravity, 5.83 luster, metallic color and streak, dark gray to black opaque. 

Metal colorants such as copper sulfate, ferricyanide, and ferrocyanide compounds can be irritating or highly toxic. If a colorant reacts with the metal, irritating acid fumes can be released. 

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