how does adding copper to gold change the economic value of the gold and the properties of the gold?

Answer 1

The addition of copper to gold is a way to decrease the amount of gold in an object (actually it decreases the percent gold in the product). 24-k gold is pure gold (100%) so 14-k, a popular gold content, is a little more than 50% gold so the object can be sold for less than if it were 100% gold. Also, and this is very important, 24-k gold is soft and would scratch easily. After a little use, the gold object, such as a ring, would lose much of its luster because of the dents and dings on the ring. The addition of copper (or nickle) forms an alloy which is much harder than pure gold. The three most popular gold contents are 18-k, 14-k, and 10-k.