Diamonds Random Facts | 1 comment Most diamonds on the Earth’s surface are between 1 and 3 billion years old. Fact source 1 Comment Ross on October 5, 2016 at 1:08 pm This isn’t a fact that diamonds are billions of years old. We cant date back that far so it is an estimated time. And still it is far fetched.. Reply Submit a Comment Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website This site uses Akismet to reduce spam. Learn how your comment data is processed.