White gold is gold alloyed with one or more white metals, typically nickel, silver, platinum or palladium. Gold is never white in its pure form, and pure gold is too soft and costly for most uses. Rolex is one watchmaker that casts its own 18 ct white gold.
What colour is white gold?
White gold is not pure white. Its colour can shade into pale yellow, brownish or very light pink tones. Because gold itself is yellow, the alloy keeps a slight yellow tint when it is left unplated. White gold is usually given a rhodium plating. The plating wears away over time and must be redone. Grey gold, a related alloy, is made mostly from gold and palladium. Watchmakers use it for its pale colour, its good workability and its resistance to corrosion.
What does 18 karat mean in white gold?
The karat figure shows how much pure gold an alloy holds. Pure gold is 24 karat. The 18-karat grade of white gold is 75% pure gold. The cheaper 14-karat grade is 58.3% gold. The rest is made up of the white metal or metals added to the alloy. Rolex makes its own 18 ct white gold in an in-house foundry, where it also casts yellow and Everose gold. The precious metals are melted at temperatures above 1,000 °C to form the alloy.
Where it comes from
An early white gold made of gold, palladium and nickel was developed in Germany. A patent for it was filed on 30 April 1913. Karl Richter of Pforzheim received the patent on 28 December 1915. The First World War had broken out, so few people knew of Richter’s alloy and little of it was made. David Belais produced an 18-karat white gold in 1917. Yet a 1926 US appeals court decision said jewellers had been using white gold for many years. That suggests the metal existed before Belais’s alloy.
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