Diamonds are forever. They are an amazing product of Earth's natural processes and have come to symbolize a commitment of eternity. We lay out some amazing facts about colored diamonds and colorless diamonds.       4 Amazing Diamond Facts The average yield in most diamond mines is 1 part diamond to 1,000,000 parts rock. It takes between 1 billion and 3.3 billion years for a diamond to grow. The oldest diamond is approximately 3.2 billion years old and the youngest is over 900 million years old. Diamonds are very rare. Of five million diamonds mined, only one million are jewelry...