White gold is an alloy made from pure gold and other metals such as silver, nickel, or palladium, which gives it a white color. The purity of white gold is measured in karats (K), the same as yellow gold. The most common purity levels for white gold are 14K and 18K, although it can also be found in 10K, 22K, and 24K.

14K white gold comprises 58.3% pure gold and 41.7% other metals, while 18K white gold shall contain 75% pure gold and 25% other metals. The higher the karat of white gold, the higher the percentage of pure gold, which can affect its color, durability, and value.

While white gold is often rhodium-plated to enhance its white color and shine, it can wear off over time and may need to reapply by a jeweler to maintain the desired appearance.