What does 730 mark on gold mean?

The mark "730" on gold indicates that the metal is 73.0% pure, or 18 karats (since 24 karats is pure gold). It signifies that out of 1000 parts, 730 are gold, while the remaining 270 parts consist of other metals, often used to enhance durability and alter color. This mark is commonly found on gold jewelry and items, reflecting a balance between purity and practicality.