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What does a 24-karat gold rating mean?

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A diagram showing the periodic table entry for gold, with the symbol Au, atomic number 79, atomic weight 196.96657, electron configuration, and labels for its properties as a solid transition metal with a face-centered cubic crystal structure. — gold The precious metal gold is a chemical element with the symbol Au. Its square on the periodic table details some of its properties, including its atomic weight, atomic number, and crystal structure.

A 24-karat rating indicates that an object is composed of pure gold.

The karat system measures the fineness or purity of gold, where one karat represents $^{1} /_{24}$ part of the whole. Because pure gold is highly malleable and soft, it is often mixed with other metals to create an alloy; the karat number reflects how many parts of that total are gold. Therefore, 24-karat gold signifies that the material consists entirely of gold, with no other alloying metals present.1