Jewelry pieces made in the United States do tarnish because precious metals need to be mixed with jewelry alloy metals so that they can be used to make jewelry. Copper, nickel and brass does the hardening while iridium does the softening. Pure gold is 24k and your ring is most likely 14k. Now you know. Your gold actually contains 14 parts gold and 10 parts nickel, copper and zinc.
Jewelers always explain content in term of parts gold.
Another way is to explain content in terms of percentages. Platinum is one of the strongest and most enduring jewelry metal. Platinum is ideal for jewelry that's worn everyday because it shows little wear. In the United States platinum jewelry generally contains anywhere from 85 to 95 percent pure platinum. Now we have a question that could be related to one's life style and we are going to hedge with our response.