Talking about gold

Metals used in the casting process

There are three main types of gold used in the jewellery manufacturing process:

• White Gold — This is yellow gold that is generally mixed with nickel and then plated with rhodium: a silvery white metal that gives white gold its shine and luster. The plating process involves dipping the jewelry into a solution containing rhodium, then running an electric current through it to bond the rhodium particles to the surface. This plating process needs to be redone periodically because the rhodium will wear off over time. White gold can also be made by mixing gold with palladium for people who are allergic to nickel.

• Yellow Gold — Yellow gold is typically alloyed with copper, silver or zinc, with the gold taking on a more reddish or greenish hue depending on the metal of which it is mixed.

• Rose Gold — The pinkish color of rose gold is the result of yellow gold being alloyed with different levels of copper and silver.

The following chart explains how much gold is present in the different karats:

• 24K = 99.9 percent gold

• 22K = 91.6 percent gold

• 18K = 75 percent gold

• 14K = 58.5 percent gold

• 10K = 41.7 percent gold