Friday, January 29, 2010

gold digger

While pure gold is yellow in color, gold can also appear to have other colors. These colors are generally obtained by alloying gold with other elements in various proportions. For example, alloys which are mixed 14 parts gold to 10 parts alloy create 14-karat gold, 18 parts gold to 6 parts alloy creates 18 karat, and so on. This is often expressed as the result of the ratio, ie: 14/24 equals 0.585 (rounded off), and 18/24 is 0.750. There are hundreds of possible alloys and mixtures, but in general the addition of silver will color gold green, and the addition of copper will color it red. A mix of around 50/50 copper and silver gives the range of yellow gold alloys the public is accustomed to seeing in the marketplace.

White gold

White gold is an alloy of gold and at least one white metal, usually nickel or palladium. Like yellow gold, the purity of white gold is given in karats. White gold's properties vary depending on the metals and proportions used. As a result, white gold alloys can be used for different purposes; while a nickel alloy is hard and strong, and therefore good for rings and pins, gold-palladium alloys are soft, pliable and good for white gold gemstone settings, sometimes with other metals like copper, silver, and platinum for weight and durability, although this often requires specialized goldsmiths. The term white gold is used very loosely in the industry to describe karat gold alloys with a whitish hue. Many believe that the color of the rhodium plating, which is what they see on many commercial pieces, is actually the color of white gold. The term white covers a large spectrum of colors that borders or overlaps pale yellow, tinted brown, and even very pale rose. The jewelry industry often hide these off-white colours by rhodium plating.

Rhodium-plated white gold wedding ring

About one person in eight has a mild allergic reaction to the nickel in some white gold alloys when worn over long periods of time. A typical reaction is a minor skin rash.[1] White gold alloys made without nickel are less likely to be allergenic.

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