White gold: nickel or palladium alloys?
White gold jewelry has been both a blessing and a curse to manufacturers as well as clients. The blessing is that you can get the look of Platinum for about 1/4th the cost. The curse is that 14k white gold is still 58.4% pure gold & 18k gold is 75% pure gold. Pure gold is yellow. To make it white manufacturers add nickel or palladium as a whitening alloy. Nickel is cheaper, but corrodes and turns yellow over time. Palladium does not yellow and wears better over time, but is more expensive.
Nickel Alloy
14k nickel white is the formula most used by commercial jewelry manufacturers in the USA. Nickell is an inexpensive alloy and very white. 14k nickel white (14KW), often called "standard white", "bright white", or "soft nickel white", is easy to cast, finish and set translating into less expensive 14KW gold jewelry. The problem with 14KW jewelry is that nickel is a ferrous metal and is prone to stree cracking and corrosion. It is also yellow tinted in color. Chlorine and bromide (found in cleaning agents, hot tubs, swimming pools, etc.) react to the nickel and other alloys in 14KW causing corrosion just like rust on iron. Nickel is also brittle and will crack over time due to the stress of everyday wear. In commercial jewelry PRICE trumps QUALITY, so all 14KW jewelry is RHODIUM plated to look more like platinum. But the plating will wear down within weeks exposing the jewelry's true color....yellowish white.