When thinking over the associations being evoked in our minds by the word 'gold', we will undoubtedly find a great variety of them related to history and treasure, luxury and prosperity. Undeniably, it is the most symbolic and emotive metal no way compared to cheap tinsel of costume jewellery. From time immemorial people have got used to correlate this metal with yellow colour. Yet, these days we more and more often encounter the so-called 'white gold'. To tell the truth, the name itself is confusing, as gold cannot be white by nature. So, is white gold a natural phenomenon or just another artefact?
To be exact, there is no such thing as 'white gold'. When specialists speak of white gold jewellery, they mean white gold alloys which appear white, silvery, or grey. It is very rare that you find pure gold. 9 carat gold is only 9/24ths (37.5%) gold. The rest 62.5% consists of other metals. 18 carat gold is 75% gold, the other 25% being other metals. 22 carat gold is 91.66% gold, the rest 8.33% being other metals. The degree of another metal you put in and the type of the metal you use determine the colour of the product.
Gold itself is a yellow metallic element, but in its pure form it is too soft to be used for general jewellery purposes. Usually gold is mixed with other metals to produce an alloy, which is simply a mixture of two or more metals. Throughout history, most people preferred the colour of gold jewellery to remain close to that of pure gold itself, and so most jewellery has historically been made by using yellow gold alloys. Still, if gold is mixed not with copper and silver to be the components of most yellow gold alloys, but with nickel, zinc, or palladium we get the original cold beauty of white gold jewellery.
White gold alloys became popular in the 1920-s when substituted platinum, which was quite expensive, needed greater temperatures than gold while processing, and was generally considered harder to work with than gold. At least three different 'recipes' of gold 'bleaching' appeared during the 1920-s.
The commonest metal which causes a significant bleaching effect on gold is nickel. It has the advantage of being inexpensive, and also provides -- in 18 carat alloys -- a good colour match for platinum. Still, there is also a dark side of the moon in the form of dermatitis caused by the metal in question through allergic reactions when worn in contact with the skin. It is also considered slightly carcinogenic.
Currently the EC Regulations covering the use of nickel in jewellery are being implemented, and soon all or most new white gold jewellery sold in the Community will have to be nickel-free, or at least 'nickel-safe'. These days most American and Italian white gold alloys are nickel-added.
The other metal which is ideal as a constituent of white gold alloys is palladium. It doesn't cause any allergic reactions, but its disadvantages are the price and a high melting point. Although, jewellery manufacturing and repair equipment has been improved recently, which fact allows workshops overcoming this sad truth.
Other possible whiteners include silver, platinum, chromium, cobalt, tin, zinc, and indium. Silver would be an ideal constituent performing excellent working properties, but, unfortunately, having little bleaching effect. Copper does not tend to whiten, but is used to improve the ductility of most white gold alloys.
White gold jewellery is an excellent company when attending posh night spots, or just going everyday shopping. It is pierced with splendor and dignity, which ordinary costume jewellery is deprived of.