The relative durability of gold alloys is determined by their gold content. Lower karat gold, such as 10k, contains a higher percentage of alloyed metals compared to higher karat gold like 14k. These alloyed metals, which often include copper, nickel, or zinc, contribute to the overall hardness and resistance to scratching.
The presence of these additional metals strengthens the resulting alloy. Jewelry frequently exposed to wear and tear may benefit from a lower karat composition. Throughout history, jewelers have balanced gold purity with practical considerations, selecting karat levels suitable for specific applications and intended use.