When travelling internationally, you are allowed to bring in a certain amount of cash without having to declare it. The maximum amount that you're allowed to bring in will vary depending on the country, but it's typically in the ballpark of $10,000-$15,000. If you have more than this amount, you will need to declare it at customs. In addition to cash, you're also allowed to bring in a certain amount of 'cash equivalents'. This includes things like traveler's checks, gold bullion, and other precious metals or stones. Again, the maximum amount will vary depending on the country. If you often move around and want to travel with some of your gold as a kind of insurance policy, pay careful attention to what countries you’re flying through and what their attitudes towards gold are. Many will treat gold as a cash equivalent. If you’re carrying gold valued over a country’s declarable amount, you’ll be asked a lot of questions at the very least.