Understanding White Gold
In its purest form (24ct), gold is yellow in colour and too malleable to be suitable for most jewellery. To give pure gold the properties required to make fine jewellery, other metals are added, which creates a gold alloy. The purity of gold in the material is represented by the carat, for example, 18ct gold is 75% pure gold and 25% other metals.
When creating white gold, white coloured metals are mixed with pure gold to create an alloy. The alloy colour will vary from slightly off white through to a subtle yellow depending on the choice and concentration of metals used. Rhodium plating is then used to give a whiter, brighter finish. Over time, particularly on rings and bracelets, this plating will wear off revealing the base colour of the alloy underneath. Different white gold alloys may look the same when new, but with normal wear, the true colouring underneath will be revealed. A more yellow coloured alloy will require more regular maintenance to restore its original appearance.
Palladium is the premium metal for mixing with pure gold to make white gold as it gives a whiter base colour, a better lustre, and it is hypoallergenic. The cheaper and common alternative to palladium is nickel. When used as an alloy in white gold, nickel will result in an inferior base colour and lustre, and it can cause an allergic reaction in as many as one out of eight people.