Is gold classified as a precious metal?

Gold is a precious metal, defined by its resistance to acids and its near-total chemical inertness with most other materials. These properties make it one of a small group of metals, alongside platinum and silver, that resist corrosion without special treatment. For jewelry, pure 24-carat gold is too soft to hold a setting securely, so it is alloyed with copper, silver, or palladium to increase durability and shift its color. That alloying process produces yellow gold, white gold, and rose gold from the same base element. Carat measures gold purity as a fraction of 24: 18-carat gold contains 18 parts gold and 6 parts other metal, or 75% gold by weight. Note that gold carat is a purity ratio, not the weight unit used to grade diamonds. Higher carat means higher gold content, but also a softer, more malleable piece. For lab-grown diamond rings, 18-carat gold is the most common setting choice, balancing purity with structural strength.